JP2006025642A - Weed controlling sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a weed controlling sheet that has excellent mechanical strength and durability, low light transmittance, accordingly has high herbicidal effect and no adverse effect by sunlight reflection. <P>SOLUTION: The weed controlling sheet comprises a cloth-like body made of uniaxially stretched yarn of a thermoplastic resin, has ≤6.0% percentage of void and 70-95% accumulated light-shielding ratio in the range of 380-780 μm wavelength. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a weed suppression sheet, and more particularly to a weed suppression sheet having high strength, excellent durability, and capable of preventing overgrowth without killing weeds.

  Conventionally, weeds have been prone to grow on the bank of river banks, banks of fields, banking, road embankments, etc., and weeds often cause pests in nearby crops. It is necessary to take measures to cut weeds or prevent weeds with chemicals. However, grass cutting requires labor, and herbicide spraying is not preferable from the viewpoint of environmental destruction.

  For this reason, a sheet is laid on the target ground to block sunlight necessary for the growth of weeds or to block rainwater infiltration to eliminate weeds (Patent Documents 1, 2, and 3). ), These weeding sheets are intended to eliminate weeds, and in areas where weeding sheets are laid, the weeds are completely killed by blocking sunlight or moisture.

  However, the embankment slope has a lot of sediment loss and needs to be prevented. Plant settlement is effective in preventing soil runoff, and weed growth can prevent soil runoff. However, when weeds are completely killed, the effect of fixing the soil by the roots of the plant cannot be used, and the roots of the weeds that had grown before laying are corroded and disappeared, so that the soil It becomes porous and rainwater permeates and softens, so that the soil is washed away, and there is a problem that landslides occur on the slope.

  Therefore, even when weeds need to be avoided, it is not preferable to kill the weeds, and it is desirable to prevent the growth of parts on the ground surface with the roots in a healthy state without causing the weeds to die. .

  In addition, in order to suppress the growth of weeds by laying a sheet, various performances are required as a sheet, for example, mechanical strength is required to walk on it, and it has excellent corrosion resistance. It is also necessary to have good durability. Furthermore, in order to prevent weeds, it is required that the light transmittance is low, and it is also necessary that the environment is not adversely affected by the reflection of sunlight.

From the knowledge of the present inventors, no sheet satisfying all such requirements has been obtained with conventional sheets.
JP 2000-93012 A 4-52727 JP-A-10-262472

  The present invention provides a weed suppression sheet that is high in strength, excellent in durability, and capable of preventing overgrowth without killing weeds.

  The present invention has been made as a result of intensive studies to achieve this object. Specifically, the present invention comprises a cloth-like body formed of a uniaxially drawn yarn made of a thermoplastic resin, and has a porosity of 6.0%. Hereinafter, a weed suppression sheet is provided in which the integrated light blocking ratio in the wavelength range of 380 to 780 mμ is 70 to 95%.

Further, the present invention provides the above-mentioned weed suppression sheet having a cloth-like body having a water permeability of 1 × 10 ⁻³ to 1 × 10 ⁻⁰ , the above-mentioned weed suppression sheet having a uniaxially stretched yarn made of flat yarn, and a thermoplastic resin The above weed suppression sheet comprising an olefin polymer, and a laminated uniaxially stretched yarn in which a cloth layer is laminated on at least one surface of a base layer with a resin layer having a melting point lower than that of the base layer. The above weed suppression sheet is provided.

  Furthermore, the present invention provides the above-mentioned weed suppression sheet in which the cloth-like body is colored in green, and the above-mentioned weed suppression in which the cloth-like body is locked to the soil surface with a thermoplastic resin or a metal pile material. A sheet is provided.

  The present invention has high mechanical strength and excellent durability, and can suppress the growth without causing weeds to die, and is excellent in the effect of preventing surface soil loss and slope failure.

  As shown in FIG. 1, the weed suppression sheet 1 of the present invention is constituted by a cloth-like body 3 formed using uniaxially stretched yarns 2 formed by uniaxially stretching a thermoplastic resin imparted with light shielding properties.

  In the present invention, the uniaxially stretched yarn 2 forming the weed suppression sheet 1 broadly means a long product that can form a sheet-like body, and includes a linear body such as a ribbon-like body, a string-like body, or a monofilament. These are twisted as needed.

  The uniaxially stretched yarn 2 may have any structure. For example, as shown in FIG. 3 (A), a thermoplastic resin film is slit to a predetermined width and uniaxially stretched to form a tape-like flat yarn. Further, as shown in FIG. 3B, it is also possible to use a split yarn having a number of cuts 5 and 5 in the tape-like body. Furthermore, as shown in FIG. 3 (C), the tape-shaped body can be provided with ultra-thin longitudinal ribs 6 and 6, and by providing the rib 6, the reflected light of the sun is scattered and the influence on the environment is reduced. can do.

  In addition, a round shape, an oval shape, a square shape, a polygonal shape, and other irregular shapes can be used. Further, a mixture of different resins is extruded into filaments, and the danline that is fibrillated by splitting between the resins is formed. By using it, it is possible to increase flexibility. Moreover, one piece can be used alone as a woven yarn, and several pieces can be bundled and used.

  The uniaxially stretched yarn 2 may be a single layer as shown in FIG. 4 (A), or on 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 a laminated uniaxially stretched yarn, and the surface layer 8 can function as a bonding layer or a matte layer. Further, the surface layer 8 may be a seascore structure as shown in FIG. 4D and a side-by-side method as shown in FIG.

  As the thermoplastic resin constituting the monolayer of the uniaxially stretched yarn 2 or the base layer 7 of the laminate, a resin having a large stretching effect, generally a crystalline resin is used. Specifically, high-density polyethylene, medium density Polyolefins such as polyethylene, polypropylene, ethylene / α-olefin copolymers, olefin polymers such as ethylene / vinyl acetate copolymers, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6 and nylon 66, acrylonitrile, vinylon Etc. can be used. Of these, olefin polymers such as high-density polyethylene, medium-density polyethylene, linear low-density polyethylene, and polypropylene are desirable from the viewpoint of processability and economy.

  The surface layer 8 is used to join the uniaxially stretched yarns 2 after the uniaxially stretched yarns 2 are woven, and a thermoplastic resin having a lower melting point than that of the thermoplastic resin constituting the base layer 7 and having an excellent heat fusion property is used. It is done.

  Specifically, olefins such as high-pressure low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, ethylene / propylene copolymer, ethylene / α-olefin copolymer, ethylene / vinyl acetate copolymer, etc. Polymers, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon 6 and nylon 66 can be used, and the melting point of the base layer is lower than that of the base layer, preferably 20 ° C. or higher. A plastic resin is selected. In particular, olefin polymers such as high-pressure method low-density polyethylene, high-density polyethylene, linear low-density polyethylene, and polypropylene are desirable, and linear low-density polyethylene polymerized using a metallocene catalyst is particularly preferable.

  Furthermore, an inorganic filler can be added to the thermoplastic resin forming the uniaxially stretched yarn 2. As the inorganic filler, those known per se as thermoplastic resin additives can be used. For example, talc, clay, mica, calcium carbonate, barium sulfate, wollastonite, zeolite, hydrotalcite, aluminum hydroxide Magnesium hydroxide, calcium silicate, etc. can be used. By blending an inorganic filler, light shielding properties can be imparted or weaving properties can be improved. The compounding quantity of an inorganic filler is 1 to 40 weight% normally, Preferably it is 3 to 30 weight%.

  The thermoplastic synthetic resin that forms the uniaxially stretched yarn 2 can be blended with various additives as necessary. Examples thereof include phenolic, organic phosphite, phosphite and other organic phosphorus, thioether, and the like. Antioxidants; Antistatic agents; Dispersants such as bisamides, waxes, and organometallic salts; Chlorine scavengers such as carboxylates of alkaline earth metal salts; Amides, waxes, organometallic salts, Ester-based lubricants; Hydrazine-based, amine-acid-based metal deactivators; Brominated organic and phosphoric acid-based flame retardants; Organic pigments; Inorganic pigments; Metal ion-based inorganic and organic antibacterial agents, etc. can do.

  Moreover, the light-shielding property can be enhanced by coloring the uniaxially stretched yarn 2. The coloring color is not intended to limit the present invention, but is preferably a calm color so as not to damage the environment, and is preferably black, green, brown, or the like. Among these, it is preferable to color green from the viewpoint of harmony with the environment or the effect of suppressing the growth of weeds.

  These additives are appropriately combined and blended in any process for producing the material composition of the base layer 7 and the surface layer 8. The blending of the additive may be prepared by mixing at a predetermined ratio using a kneading device such as a conventional known twin screw extruder, Banbury mixer, kneader, mixing roll, and melt-kneading the mixture. A so-called master batch having a high concentration may be prepared and used after being diluted.

  When a laminated uniaxially drawn yarn is used, as a means for forming a laminated film as a molding material of a laminated flat yarn or a laminated split yarn, a film that becomes a base layer 7 and a film that becomes a surface layer 8 are formed in advance and dried. Means for making multiple layers using a laminating method or a thermal laminating method, a method of coating a thermoplastic resin to be the surface layer 8 on the surface of the film to be the base layer 7, and extrusion laminating the surface layer 8 to the film to be the base layer 7 formed in advance Or a known method such as extrusion molding as a laminated film by a multilayer coextrusion method may be used as appropriate, but in terms of ease of molding and cost, and adhesiveness between each layer of the product A method of obtaining a laminated body of the base layer 7 and the surface layer 8 in one step by a multilayer coextrusion method is desirable. The seascore structure or side-by-side structure is generally based on a coextrusion method.

  Further, as a means for stretching to make the uniaxially stretched yarn 2, after stretching the film that becomes the base layer 7 in the uniaxial direction, the thermoplastic resin that becomes the surface layer 8 may be laminated, and this may be slit into a tape shape, Or it can also obtain by extending | stretching to a uniaxial direction before slitting the laminated film in which the base layer 7 and the surface layer 8 were laminated | stacked, or after slitting. The draw ratio is usually about 3 to 10 times.

  The thickness of the uniaxially stretched yarn 2 is not limited and can be arbitrarily set according to the purpose, but is generally 500 to 10,000 decitex, preferably 1000 to 5000 decitex. In the case of yarn, the yarn width is 0.3 to 200 mm, preferably 1.0 to 100 mm, and the yarn thickness is 5 to 500 μm.

  When the layer structure of the elongated filament 2 is a three-layer structure, generally, the thickness composition ratio is set to be: surface layer: base layer: surface layer = 1: 98: 1 to 25:50:25.

  As shown in FIGS. 1 (A) and 1 (B), the drawn filament 2 thus obtained can be woven into a plain weave to form a cloth-like body 3. In addition, it can be made into a cloth-like body 3 by weaving in a twill weave, a twill weave, a knit weave, a double weave, a double weave, a knit weave, etc. It is also possible to make a cloth-like body. As a loom for weaving, a known loom such as a circular loom, a slewer loom, a water jet loom can be used. Further, as shown in FIG. 2, a plurality of elongated filaments 2b are arranged in parallel, and another elongated filament 2a is arranged in parallel in the direction intersecting with the elongated filament 2b, and the intersection is thermally bonded. It can be set as the cloth-like body 3 which consists of the cross-bonded cloth (soft). In general, the number of driven fabric bodies 3 is 3 to 50 / 25.4 mm.

  In this invention, when it forms in cloth shape and it is set as the weed suppression sheet | seat 1, it has the characteristics in the integrated light-shielding rate of the range of wavelength 380-780mmicro being 70-95%, Preferably it is 80-90%. As a method of controlling the integrated light shielding rate, a method of adding a filler or a pigment to the base layer 7 or the surface layer 8 constituting the uniaxially stretched yarn 2 or both is effective. When the weed suppression sheet 1 of the present invention is formed into a cloth shape to form the weed suppression sheet 1, the stretched filaments 2 are woven or knitted with a driving density such that the integrated light shielding rate falls within the above range. Formed by.

In the present invention, the weed suppression sheet 1 generally has a ratio of gaps formed between the elongated filaments 2, that is, a porosity of 6% or less, preferably 0.1 to 5%. When the porosity exceeds 6%, it becomes difficult to obtain a necessary light shielding rate. Further, since the water shielding property is lowered and the amount of rainwater permeated is increased, the effect of suppressing the growth of weeds is lowered. It is preferable that the size of the gap, that is, one gap is a direct line in a round shape and 3 mm or less, preferably 1 mm or less, in a polygon. In addition, when using the weed suppression sheet | seat 1 with a large area, it is desirable that a porosity is 0.1% or more, and it becomes easy to prevent weeds from dying by giving a space | gap. Moreover, mass is generally 50-500 g / m < ² >. When the mass is less than 50 g / m ^2, it is difficult to ensure the light shielding property, and when the mass exceeds 500 g / m ² , the economy is deteriorated.

The water permeability of the weed suppression sheet 1 is such that the water permeability coefficient (cm / sec) based on JIS A1218 is 1 × 10 ⁻³ to 1 × 10 ⁻⁰ , preferably 1 × 10 ⁻² to 1 × 10 ^−1. Is desirable.

  Moreover, in order to prevent fraying of an edge part, it is also desirable for the weed suppression sheet | seat 1 to heat-weld an edge part by heat-cutting using a hot blade, and also to prevent fraying by tacking in. it can.

  Furthermore, fraying can also be prevented by applying a molten thermoplastic resin, hot melt agent, or water-based adhesive to the cloth-like body. Lamination and application for fraying prevention are usually performed at predetermined intervals. It is desirable to carry out in a state. Moreover, when a laminated body is used as the uniaxially stretched yarn 2, fraying can be prevented by heat welding. Moreover, it is also possible to attach the reinforcement rope 11 to this invention weed suppression sheet | seat 1 as shown to FIG. 5 (A).

  Further, as shown in FIG. 5 (B), it is preferable to weave yarns 9 of different colors into the weed suppression sheet 1 at a predetermined interval. Positioning is facilitated when a sheet is laid by interweaving yarns 9 of different colors or locked with system stoppers 13 such as pins and piles. The positioning mark can also be provided by printing a line mark on the surface using printing ink.

 The weed control sheet 1 of the present invention can be laid on the bank of a field, on the bank of a river, on the back of a bank on a railway line, on a road bank slope, on a road median strip, on the lower part of a steel tower, etc., and to fulfill the weeding function.

  As shown in FIG. 6, this invention weed suppression sheet | seat 1 can be fixed by laying in the place which should be weeding processing with overlap allowance, and latching with locking tools 13, such as a pin and a pile. As the locking tool 13 such as a pin or a pile, a hail-like body made of metal, thermoplastic resin, FRP, or the like, or a U-shaped body can be used.

  The weed suppression sheet 1 of the present invention is generally laid on the surface of a place where weeding treatment is to be performed, but can also be laid as an underlay material at a laid place such as chestnut.

Test-1
A polyethylene (manufactured by Nippon Polychem Co., Ltd.) containing 1.0% by weight of a green pigment (cyanine green type) was molded by an inflation molding method using a melt extruder, and slit using leather. The slit resin tape was stretched about 7 times on a hot plate at a temperature of 110 to 120 ° C., and then subjected to a relaxation heat treatment of 6% in a hot air circulation oven at a temperature of 120 ° C. and wound around a winder.

  At this time, stretched filaments having different thicknesses were prepared depending on the thickness of the original film and the stretch ratio, and these were woven into plain weaves to obtain sheets having a light shielding rate shown in Table 1. The obtained sheet was cut into 2 m × 2 m to obtain a green color weed suppression sheet.

(Laying test)
1 m of each weed suppression sheet obtained after mowing grassland where Enocorogusa (cat moth), Chikarashiba (Episode serrata), Golden-spotted Egret (Mesiba), Suzumeehie, Susuki (Obana), American Sendangsa (Seitachokogi), etc. grows with a mower. The four corners were locked with piles. Sixty days after that, the state of weed growth was observed and evaluated. The results are shown in Table 1.

  The evaluation rank of weeds was as follows.

A: Completely died B: About half died
C: Not dead but hardly growing D: Growing to some extent E: Thriving

  As for the weed state, B to D are usable ranges, C is most preferable, and A and E are not suitable for use.

Test-2
The same experiment as in Test-1 was performed except that the light shielding ratio and the void ratio were as described in Table 2. The results are shown in Table 2.

  The weed control sheet of the present invention is laid on the bank of rivers, on the banks of fields, or on embankment slopes of railways and roads, etc. to prevent weeds from growing, and to prevent runoff of landslides, landslides, etc. it can.

(A) which shows this invention weed suppression sheet | seat is a top view, (B) is a longitudinal cross-sectional view The longitudinal cross-sectional view which shows the other example of this invention weed suppression sheet | seat The perspective view which shows the example of the uniaxially stretched yarn used for this invention weed suppression sheet | seat The longitudinal cross-sectional view which shows the example of the uniaxially stretched yarn used for this invention weed suppression sheet | seat (A) which shows the example of this invention weed suppression sheet | seat is a longitudinal cross-sectional view, (B) is a perspective view The perspective view which shows the laying example of this invention weed suppression sheet | seat

Explanation of symbols

1, weed suppression sheet 2, uniaxially stretched yarn 3, cloth-like body 5, notch 6, rib 7, base layer 8, surface layer 11, reinforcing rope 13, locking tool

Claims (7)

  A weed comprising a cloth-like body formed of a uniaxially drawn yarn made of a thermoplastic resin, having a porosity of 6.0% or less and an integrated shading ratio in a wavelength range of 380 to 780 mμ of 70 to 95%. Suppression sheet. The weed suppression sheet according to claim 1, wherein the cloth body has a water permeability coefficient of 1 x ^10-3 to 1 x ^10-0 .   The weed suppression sheet according to claim 1 or 2, wherein the uniaxially stretched yarn comprises a flat yarn.   The weed suppression sheet according to any one of claims 1 to 3, wherein the thermoplastic resin comprises an olefin polymer.   The cloth-like body is composed of a laminated uniaxially stretched yarn in which a surface layer made of a resin having a melting point lower than that of the base layer is laminated on at least one surface of the base layer, and the warp and weft are thermally bonded. Weed suppression sheet.   The weed suppression sheet according to any one of claims 1 to 5, wherein the cloth-like body is colored green.   The weed suppression sheet according to any one of claims 1 to 6, wherein the cloth-like body is locked to the soil surface with a thermoplastic resin or a metal pile material.

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