JP2018044355A - Weed-proof sheet and weed-proof method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a weed-proof sheet having weed-proof effect.SOLUTION: A weed-proof sheet comprises quick-hardening powder containing calcium aluminate and gypsum of 1.3-3 in CaO/AlO(the mole ratio) filled in clearances in a three-dimensional solid sheet formed by connecting two mesh-like sheets arranged at intervals of 1-10 mm by connection yarn, where a water soluble film is laminated on one or both surfaces of the mesh-like sheets. It may also contain one or two or more selected from γ-2CaO.SiO, fly ash, silica-quality fine powder, a blast furnace slag, and limestone fine powder, or a fine aggregate.SELECTED DRAWING: Figure 1

Description

The present invention relates to a herbicidal sheet and a herbicidal construction method. The present embodiment relates to a herbicidal sheet and a herbicidal construction method for preventing the growth of weeds on, for example, surrounding ground such as roads, railways, parks, rivers, solar power plant sites, farmland, power facility sites, and the like.

  Weeds are used for roads, railways, parks, rivers and other surrounding grounds, solar power plant sites, farmland, power facility sites, etc., as weeds grow, which may cause functional problems. There is a need to. In recent years, secondary products such as concrete and mortar and synthetic resin sheets have been used in place of manual mowing and the use of herbicides as means for suppressing the growth of weeds. Since secondary products such as concrete and mortar are heavy, it is necessary to use heavy machinery to install them, which is a large-scale work. Synthetic resin sheets are thin and light, so they can be easily installed by hand. However, they often blow or break in the wind, so there are many problems with durability.

  A herbicidal method using a solidifying material has also been proposed. For example, a method has been proposed in which a material containing a magnesium oxide-based solidifying material as a herbicide component is sprayed on or mixed with the soil surface, and moisture is added to solidify (Patent Document 1). This method suppresses the germination of weeds by improving the strength of the soil, but when mixed with soil, seeds already contained in the soil may germinate. In addition, it is necessary to knead water and materials on site, and in the case of carrying out a large area in particular, it is a mechanical construction using heavy machinery such as a mixer or a compactor. Although it is possible to mix by hand using a scoop, etc., there is a problem that the mixed soil strength varies because it is difficult to perform uniform mixing, and a sufficient herbicidal effect cannot be exhibited. In addition, when the solidified material is constructed on a steep slope or the like, it takes a long time for a person to enter the work on the steep slope, which is more labor intensive and dangerous work than installing a synthetic resin sheet.

  A resin composition comprising a vinyl chloride resin containing a plasticizer and an epoxy resin and / or an unsaturated polyester resin is applied to a lattice-like fiber sheet knitted and woven with synthetic fiber yarns having a total fineness of 1000 denier or more. A grid-like sheet (Patent Document 1) is described.

  It is described that a three-dimensional solid sheet is used in the field of civil engineering and architecture. The three-dimensional solid sheet is a three-dimensional sheet in which two base materials arranged so as to have a specific interval are connected by a connecting thread. As the substrate, a mesh sheet is used as the sheet substrate. In the civil engineering / architecture field, a reinforcing material for embedded formwork (Non-Patent Document 1), a material for suppressing the lifting and cracking of surface finish materials (Patent Document 2), and connecting two sheet base materials with connecting threads. A material that forms a rigid protective layer or waterproof layer by advancing the hydration reaction of cement by spreading and spraying a sheet filled with cement powder or the like on a slope or a place to be waterproofed in the created space (Patent Document 3) ) Has been proposed.

  Non-Patent Document 1 uses a three-dimensional glass fiber as a reinforcing material for an embedded formwork and conducts an experimental study assuming application to an actual structure. The space between the three-dimensional fibers is filled with a paste-like material in which silica fume based on ordinary Portland cement, an expansion material, fine limestone powder, etc. are previously kneaded with water. The same applies to Patent Document 2 in that the paste material is filled in the gap. On the other hand, in the present embodiment, a three-dimensional solid having a laminated structure in which powder is filled in a gap of a three-dimensional solid sheet without being premixed with water and a water-soluble film is superimposed on the upper and lower surfaces of the sheet base material. It is a sheet. In this embodiment, after a three-dimensional solid sheet is installed, water is sprayed from the surface to make the sheet itself rigid. Therefore, this embodiment does not fill the gaps in the three-dimensional sheet with a material kneaded with water in advance.

In Patent Document 3, powder cement is filled in a gap between three-dimensional sheets as in the present embodiment. Since Patent Document 3 aims to construct a protective layer and a waterproof layer that are impermeable to water, for example, a seal layer using, for example, polyvinyl chloride is provided on one side. On the other hand, this embodiment is not cement but is filled with calcium aluminate having a CaO / Al ₂ O ₃ (molar ratio) of 1.3 to ₃ , and a water-soluble film is provided on one or both sides. This embodiment does not form a water-impermeable layer for the purpose of waterproofing, but considers water permeability and air permeability even if the sheet is cured by water spraying.

  Furthermore, Non-Patent Document 1 and Patent Documents 1 to 3 do not describe the use for weed prevention.

  A water-soluble sheet (Patent Document 4) for preventing weeds and a vegetation greening mat body (Patent Document 5) having a sheet for preventing weeds are known. Patent Document 4 uses a water-soluble sheet formed by mixing or sticking a leaf-absorbing herbicidal agent, and the herbicidal effect is borne by the herbicidal agent. On the other hand, this embodiment exhibits the herbicidal effect due to the strength and light shielding of the solidified product cured by the hydration reaction. Since this embodiment does not contain a medicinal ingredient that may adversely affect crops, it is highly safe.

  In Patent Document 5, a light-shielding net sheet, an entire perforated sheet, and a nonwoven fabric are stacked in that order, and a vegetation base soil having a thickness of 1 cm to 5 cm is formed thereon, and a nonwoven fabric, seeds, a water-soluble sheet ( Water-soluble paper sheet), vegetation greening mat body, characterized in that it is formed by laminating in the order of water-soluble paper sheet, whole surface perforated sheet, light-shielding net sheet, and sewing at predetermined vertical and horizontal intervals, and from a specific seed carried on the sheet It is a greening herbicidal sheet that propagates germinating plants and prevents weeds. On the other hand, this embodiment is not a herbicidal construction method for breeding a specific plant.

Inoue et al., Development of highly durable embedded formwork using three-dimensional hollow glass fabric, Papers of Japan Society of Civil Engineers, No. 760 / V-63, pp. 13-27, 2004.5

JP-A-4-327272 JP 2009-97248 A WO2007 / 144559 JP-A-6-197676 JP 2014-39507 A

That is, according to the present invention, a CaO / Al ₂ O ₃ (molar ratio) is 1 in a gap between a three-dimensional solid sheet in which two mesh sheets arranged so as to have an interval of 1 to 10 mm are connected by a connecting thread. A herbicidal sheet filled with a quick-hardening powder containing 3 to 3 calcium aluminate and gypsum and having a water-soluble film superimposed on one or both sides of the mesh-like sheet, and γ-2CaO · SiO ₂ , the quick-hardening powder is one or more selected from fly ash, siliceous fine powder, blast furnace slag and limestone fine powder, Furthermore, the weedproof sheet containing fine aggregate is a herbicidal construction method using the weedproof sheet, and after setting the weedproof sheet at a place where we want to protect the grass, it is hardened by sprinkling water on the surface. Herbicide method to solidify powder It is.

The present invention is, for example, lightweight and can be easily installed in a place where weed protection is desired, and since the filled hydraulic powder is solidified by spraying water from the surface of the grass protection sheet, the sheet itself can be rigidized for a long period of time. It exhibits a herbicidal effect.

It is a figure which shows a three-dimensional solid sheet. It is a figure which shows the mesh shape of a mesh sheet.

  The three-dimensional solid sheet of the present embodiment (hereinafter sometimes referred to as a three-dimensional sheet) is a three-dimensional sheet in which two sheets are connected by a connecting thread, and is generally commercially available. Can be used. The three-dimensional sheet is based on two sheets. In order to fill the gap with the powder, the sheet base material connected by the connecting yarn is preferably a net-like sheet base material (hereinafter sometimes referred to as a net-like sheet). The size of the mesh may be three times or more the maximum powder particle size of the powder to be filled as a guide. The mesh size is preferably 0.1 to 20 mm, more preferably 1 to 10 mm, and most preferably 2 to 6 mm. The mesh size means, for example, a center distance in the mesh long direction or a center distance in the mesh short direction.

The three-dimensional sheet is exemplified in JP-A No. 2001-234456. A cross-sectional view of the three-dimensional sheet is illustrated in FIG. In the three-dimensional sheet 1, the first mesh sheet 11 and the second mesh sheet 13 are arranged so as to have a gap. The first mesh sheet 11 and the second mesh sheet 13 are connected by a connecting thread 12. The shape of the mesh of the sheet base material constituting the three-dimensional sheet of the present embodiment is not particularly limited, but any of a rectangle, a circle, an ellipse, and a polygon can be used. In these, a polygon is preferable. Among polygons, a hexagon is preferable.
The basis weight of the three-dimensional sheet is preferably 50 to 800 g / m ² .

  1-10 mm is preferable and, as for the space | interval 14 of the 2 sheet | seat base material connected with the connection thread | yarn of the solid sheet of this embodiment, 2-8 mm is more preferable. If it is less than 1 mm, the amount of the filler is small and a sufficient herbicidal effect may not be obtained. If it exceeds 10 mm, the sheet mass becomes too heavy, and the workability may be inferior.

  The material of the three-dimensional sheet of the present embodiment is not particularly limited, and general synthetic fibers and biodegradable fibers can be used.

  The quick-hardening powder of this embodiment contains calcium aluminate and gypsum.

The calcium aluminate having a CaO / Al ₂ O ₃ (molar ratio) of 1.3 to _{3 in the} present embodiment is a mixture of calcia raw material and alumina raw material, and is fired in a kiln or melted in an electric furnace. And a substance having a hydration activity mainly composed of CaO and Al ₂ O ₃ obtained by cooling. As the calcium aluminate, amorphous calcium aluminate that is rapidly cooled after melting is preferable from the viewpoint of initial strength development after solidification.

The molar ratio of CaO to Al ₂ O ₃ is preferably 1.3 to 3.0, and more preferably 1.5 to 2.5. If the molar ratio is less than 1.3, the curing time becomes longer and the herbicidal property may be reduced, and if the molar ratio exceeds 2.5, the reaction is too fast when sprinkled to the ground via the weedproof sheet. Water may not permeate and the herbicidal properties may be reduced.

Furthermore, in this embodiment, a part of calcium aluminate CaO or Al ₂ O ₃ is alkali metal oxide, alkaline earth metal oxide, silicon oxide, titanium oxide, iron oxide, alkali metal halide, alkaline earth. A compound substituted with a metal halide, an alkali metal sulfate, an alkaline earth metal sulfate, or the like, or a compound mainly composed of CaO and Al ₂ O ₃ can be used.

The vitrification rate of calcium aluminate is preferably 70% or more, more preferably 90% or more, and most preferably 100% (amorphous) in terms of reaction activity. If it is less than 70%, the initial strength development may be lowered. As for the vitrification rate, the main peak area S of the crystalline mineral was measured in advance by a powder X-ray diffraction method for the sample before heating, then heated at 1000 ° C. for 2 hours, and then slowly cooled at a cooling rate of 1 to 10 ° C./min. Then, the main peak area S ₀ of the crystal mineral after heating by the powder X-ray diffraction method is obtained, and further, the vitrification ratio χ is calculated by using the following equation using the values of S ₀ and S.
Vitrification rate χ (%) = 100 × (1−S / S ₀ )

The particle size of the calcium aluminate, in terms of initial strength development, preferably 3,000 cm ² / g or more in Blaine specific surface area, 5,000 cm ² / g or more is more preferable. If it is less than 3,000 cm ² / g, the initial strength development may be lowered.

  The quick-hardening powder of this embodiment contains gypsum.

  As the gypsum of this embodiment, 2 water gypsum, half water gypsum, and anhydrous gypsum can be used. Among these, anhydrous gypsum is preferable in terms of strength development. As anhydrous gypsum, hydrofluoric acid byproduct anhydrous gypsum and natural anhydrous gypsum can be used. The pH when gypsum is immersed in water is preferably from a weak alkali having a pH of 8 or less to acidic. When the pH is high, the solubility of the gypsum component increases, and the initial strength development may be inhibited. Here, the pH is a value obtained by measuring the pH of the diluted slurry at 20 ° C. of gypsum / ion exchange water = 1 g / 100 g using an ion exchange electrode or the like.

The particle size of the gypsum is in a plane initial strength development and proper working time is obtained, preferably 3000 cm ² / g or more in Blaine specific surface area, 5000 cm ² / g or more is more preferable.

  50-200 mass parts is preferable with respect to 100 mass parts of calcium aluminate, and the usage-amount of gypsum is more preferable 75-150 mass parts. If the amount is less than 50 parts by mass, the long-term strength development may be impaired, and the working time may not be obtained. If the amount exceeds 200 parts by mass, the initial strength may not be obtained.

The rapid-hardening powder of the present embodiment may contain γ-2CaO · SiO ₂ .

Γ-2CaO · SiO ₂ used in this embodiment, among the compounds represented by 2CaO · SiO _2, is what is known as a low temperature phase, a high-temperature phase α-2CaO · SiO ₂ and beta-2CaO - it is different from that of the SiO _2. All of these compounds are 2CaO · SiO ₂ and have the same chemical composition, but their crystal structures are different. 2CaO · SiO ₂ present in the cement clinker is β-2CaO · SiO ₂ . β-2CaO · SiO ₂ has hydraulic properties. Γ-2CaO · SiO ₂ in the present embodiment does not have hydraulic properties, but has a property of absorbing and curing carbon dioxide in the atmosphere.

The particle size of the γ-2CaO · SiO ₂ is not particularly limited but is preferably 3,000 cm ² / g or more in Blaine specific surface area, 4,000~8,000cm ² / g is more preferable. If the Blaine specific surface area is less than 3,000 cm ² / g, the carbon dioxide in the atmosphere may be absorbed and sufficient strength may not be obtained.

The method for industrially producing γ-2CaO · SiO ₂ is not particularly limited, but in general, (1) calcium sources such as quick lime, slaked lime, and / or calcium carbonate, (2) aluminum oxide, aluminum hydroxide And / or a method of heat-treating an aluminum source such as bauxite.

  The heat treatment temperature is not particularly limited, and is preferably 850 to 1600 ° C, more preferably 1,000 to 1,500 ° C in terms of heat treatment efficiency.

The amount of γ-2CaO · SiO ₂ used in this embodiment is preferably from 2 to 60 parts by weight per 100 parts by weight of calcium aluminate and gypsum, and more preferably 5 to 40 parts by weight. If it is less than 2 parts by mass, the effect of improving the long-term strength may not be exhibited, and if it exceeds 60 parts by mass, sufficient initial strength development may not be obtained.

  The quick-hardening powder of the present embodiment can be used in combination with one or more admixtures selected from blast furnace slag, fly ash, siliceous fine powder, and limestone fine powder.

  As the blast furnace slag, blast furnace slag fine powder defined in JIS A 6206 “Blast furnace slag fine powder for concrete” can be used. As the fly ash, a fly ash specified in JIS A 6201 “Fly Ash for Concrete” can be used.

  The limestone fine powder is preferably pulverized limestone. As the limestone fine powder, an inorganic powdery substance mainly composed of calcium carbonate can also be used.

As the blast furnace slag, fly ash, and fine limestone powder used in the present embodiment, commercially available ones can be used, and are not particularly limited, but those having a brain specific surface area of 3000 cm ² / g or more. If you can use it.

  The amount of admixture used is preferably 2 to 200 parts by weight, more preferably 5 to 100 parts by weight, and 8 to 50 parts by weight with respect to the total 100 parts by weight of calcium aluminate and gypsum in terms of strength development. Is more preferable.

  The amount of blast furnace slag used is preferably 2 to 50 parts by mass and more preferably 5 to 30 parts by mass with respect to 100 parts by mass in total of calcium aluminate and gypsum. If it is less than 2 parts by mass, the effect of improving the long-term strength may not be exhibited, and if it exceeds 50 parts by mass, sufficient initial strength development may not be obtained.

  2-50 mass parts is preferable with respect to a total of 100 mass parts of calcium aluminate and gypsum, and 5-30 mass parts is more preferable. If it is less than 2 parts by mass, the effect of improving the long-term strength may not be exhibited, and if it exceeds 50 parts by mass, sufficient initial strength development may not be obtained.

  2-50 mass parts is preferable with respect to a total of 100 mass parts of calcium aluminate and gypsum, and, as for the usage-amount of a limestone fine powder, 5-30 mass parts is more preferable. If it is less than 2 parts by mass, the effect of improving the long-term strength may not be exhibited, and if it exceeds 50 parts by mass, sufficient initial strength development may not be obtained.

  The siliceous fine powder used in the present embodiment is a fine powder mainly composed of silica, and is generated when a silica fume that is commercially available or silica for use in optical fibers or semiconductor sealing materials is produced. Non-standard products can also be used.

BET specific surface area is preferably ^{10~30m 2 / g, 15~25m 2 /} g is more preferable.

  The amount of the siliceous fine powder used in the present embodiment is preferably 2 to 30 parts by mass and more preferably 5 to 20 parts by mass with respect to 100 parts by mass in total of calcium aluminate and gypsum. If it is less than 2 parts by mass, the effect of improving the long-term strength may not be exhibited, and if it exceeds 30 parts by mass, sufficient initial strength development may not be obtained.

  In the present embodiment, colloidal silica dispersed in water may be sprayed after installation of the three-dimensional sheet so as to sprinkle with water.

  In the present embodiment, a fine aggregate may be used in combination with the quick-hardening powder to form a powder.

  The fine aggregate used in the present embodiment is not particularly limited as long as it is a dry fine aggregate, but the maximum particle diameter is 1.2 mm or less so that the gap can be easily filled through the mesh sheet. It is preferable to use the fine aggregate.

  The amount of the fine aggregate used is preferably 100 to 800 parts by mass, more preferably 200 to 600 parts by mass with respect to 100 parts by mass of the powder other than the fine aggregate. As the powder, quick-hardening powder is preferable. If the amount is less than 100 parts by mass, uniform water permeability cannot be obtained when water is sprinkled, and strength development may be reduced. If the amount exceeds 800 parts by mass, strength development may be reduced.

  In this embodiment, various additives (materials) can be used as long as the effect is not hindered. For example, pigments, polymer emulsions, setting retarders, setting accelerators, short fibers, cements specified in JIS, alumina cement, bentonite, rubber powder, light-burned magnesia, herbicides, herbicides, fertilizers, glues, etc. Can be mentioned.

  In the weedproof sheet of this embodiment, a water-soluble film made of a water-soluble resin (hereinafter sometimes referred to as a film) is used as a sheet base material so that the powder filled between the sheet base materials does not fall out. It has a structure of bonding to one side or both sides. For example, it has a structure in which a film is bonded to the outside of the first mesh sheet 11 or the second mesh sheet 13. When pasting only on one side, the film is placed on the ground side. The role of the water-soluble film is to prevent the filling from spilling out. The grass prevention sheet of this embodiment solidifies the quick-hardening powder filled after installation with water. At that time, use a material that is soluble in water because the hydration of the quick-hardening powder must proceed smoothly and the film must be melted to ensure water permeability even when placed on the ground side. ing.

  The film disposed on the side that comes into contact with air (for example, the atmosphere) retains components dissolved in water in the solidified body, and can also impart a function of suppressing wear due to wind or the like.

  The method for adhering the water-soluble film to the three-dimensional sheet is not particularly limited, but adhesion by heat, an adhesion method by applying an adhesive, or the like is used.

  Although the kind of water-soluble film is not particularly limited, synthetic resins such as polyvinyl alcohol, polyethylene oxide, polyvinyl ether, polyvinyl pyrrolidone, pullulan, and cellulose derivatives and those derived from natural products can be used. In these, polyvinyl alcohol and a cellulose derivative are preferable and polyvinyl alcohol is more preferable.

  0.1-10 mm is preferable and, as for the thickness of a water-soluble film, 0.5-5 mm is more preferable.

The filling amount of the fine aggregate-containing powder with respect to the three-dimensional sheet is preferably 1 to 30 kg, more preferably 2 to 20 kg, and most preferably 5 to 15 kg per 1 m ² of the surface area of the three-dimensional sheet. If the weight is less than 1 kg, the herbicidal effect may not be achieved. If the weight exceeds 30 kg, the solid sheet does not have water permeability or air permeability when the hardened powder is cured, and the weight of the three-dimensional sheet increases, resulting in workability. May decrease. The surface area of the three-dimensional sheet refers to the surface area of the first mesh sheet 11 or the second mesh sheet 13.

  The manufacturing method of the weedproof sheet of this embodiment will not be specifically limited if it is a method which can be filled with the powder in the clearance gap between three-dimensional sheets. For example, there is a method in which a water-soluble film is attached to one side of a commercially available three-dimensional sheet, the sheet is placed on a vibrator, and the powder is uniformly filled while being vibrated. After filling, a water-soluble film may be further adhered and both surfaces may be sandwiched with the water-soluble film. If the water-soluble film melts during storage due to the influence of humidity, a release sheet that does not absorb water may be attached to cover the water-soluble film, and a water-soluble film that dissolves in warm water at 45 ° C or higher is used. You can also When using a water-soluble film that dissolves in warm water, the water sprayed on the herbicidal sheet may be warm water that is at or above the dissolution temperature.

  The installation method of the weedproof sheet according to the present embodiment is not particularly limited. For example, after weeding a portion where we want to prevent weeding and removing the cut weeds, the weedproof sheet according to the present embodiment is spread, Water is sprayed from above and solidified. In this embodiment, by spraying the surface of the weedproof sheet, the hardened powder is solidified, the weedproof sheet itself is stiffened, the effect of light shielding and strength development is exerted, and the weedproof over a long period of time. Demonstrate the effect.

  The method of spraying water is not particularly limited, but a sprayer for spraying water, agrochemicals, or the like can be used. The fixing of the sheet is not particularly limited. For example, a pin may be driven into the soil and fixed through the sheet.

  The water to be sprinkled may contain an aqueous polymer emulsion. It is considered that the polymer emulsion is formed into a film in the solidified body and further exhibits an effect of improving the solidification force of the solidified body and suppressing the outflow of alkali content.

  The amount of water spray is preferably 10 to 1000 parts by mass, more preferably 30 to 500 parts by mass, and most preferably 50 to 200 parts by mass with respect to 100 parts by mass of the quick-hardening powder.

  As the type of the aqueous polymer emulsion, commercially available ones can be used, and examples thereof include an ethylene-vinyl acetate emulsion, an acrylate emulsion, a styrene-butadiene emulsion, and a chloroprene emulsion.

  Hereinafter, the present embodiment will be described more specifically with reference to examples. The present embodiment is not limited to the following examples. The mesh size of the base material sheet used in the present embodiment is at least three times the maximum powder particle diameter of the powder.

A polyvinyl alcohol film made by drying a 10% aqueous solution of polyvinyl alcohol on one side (13 in FIG. 1) of a three-dimensional solid sheet (1 in FIG. 1) having a sheet base interval shown in Table 1 is attached with an aqueous adhesive. It was. A three-dimensional solid sheet with a polyvinyl alcohol film attached thereto was set on a table-like vibrator. While applying vibration, a quick-hardening powder consisting of 100 parts by mass of calcium aluminate c and 100 parts by mass of gypsum was filled. The filling amount of the powder is 8 kg per 1 m ² of the surface area of the three-dimensional sheet. Excess powder was removed to obtain a herbicidal sheet. Furthermore, the weed-proof sheet | seat which affixed the polyvinyl alcohol film on the other surface (11 of FIG. 1) of the three-dimensional solid sheet with the aqueous adhesive, and affixed the polyvinyl alcohol film on both surfaces was also produced, and mass was measured. The surface area of the obtained weedproof sheet is 900 cm ² . The weedproof sheet was laid on the weeded ground, and 70 parts by mass of water was sprinkled with water on 100 parts by mass of the rapid hardening powder to solidify the rapid hardening powder. The herbicidal effect was confirmed one month (28 days) after watering. The herbicidal effect was evaluated by the number of weeds. The results are shown in Table 1.
In addition, the case where it implemented according to the construction method of the commercially available magnesia type herbicide solidification material for the comparison was also evaluated. The magnesia herbicidal material was spread directly on the ground, smoothed, and then sprinkled with water. The thickness with which the magnesia-based herbicidal material was spread was 3 mm, 10 mm, and 20 mm. The amount of water spray was adjusted to 25% by mass with respect to the spread material.

(Materials used)
Three-dimensional solid sheet: A commercial product (trade name “Fusion” manufactured by Asahi Kasei Co., Ltd.), a three-dimensional solid sheet having a predetermined base material interval is used.
-The material of the connecting thread and mesh sheet is PET
Details of the base sheet (mesh sheet, corresponding to 11 and 13 in FIG. 1) are as follows.
..Mesh shape: hexagon, see FIG.
.. Mesh size: a5 mm × b3 mm, a is the center distance in the mesh long direction, b is the center distance in the mesh short direction, see FIG.
Polyvinyl alcohol film: Polyvinyl alcohol (Denka, trade name “B-17”) is dissolved in water to prepare a 10% by mass aqueous solution, cast on a glass plate to a thickness of 1 mm, and at 90 to 100 ° C. Made by drying.
Gypsum: Natural anhydrous gypsum, brain specific surface area 5100 cm ² / g, pH when gypsum is immersed in water is 6.1.
Calcium aluminate c: amorphous calcium aluminate with CaO / Al ₂ O ₃ = 2.0: Blaine specific surface area 5900 cm ² / g
Magnesia-based herbicidal solidifying material: Commercially available product (trade name “Weedproof Master” made by Ube Materials)
Water-based adhesive: Adhesive mainly composed of acrylic copolymer (manufactured by 3M, trade name “MT1000”)

(Test method)
Brain specific surface area: JIS R 5201 compliant.
Mass: The mass of the weedproof sheet having an area of 900 cm ² was measured with a weighing machine. Experiment No. 1-8 to 1-10 is the mass when laid down to be 900 cm ² .
Number of weeds: Number of weeds generated through a weedproof sheet with an area of 900 cm ²

  As shown in Table 1, the herbicidal sheet of the present embodiment has a herbicidal effect even when the thickness is reduced, and the mass is reduced, so that labor can be reduced. In general, commercially available magnesia herbicidal material has a herbicidal effect than when nothing is laid, but the solidified material cracked and weeds were generated because of its low strength. When the interval between the three-dimensional solid sheets was zero, the quick-hardening powder could not be filled into the three-dimensional solid sheet.

  A herbicidal sheet was prepared in the same manner as in Example 1 except that a three-dimensional solid sheet having a sheet base interval of 3 mm was used and the calcium aluminate shown in Table 2 was used. The cured state, the infiltration state, and the number of weeds after watering the weedproof sheet were measured.

(Materials used)
Three-dimensional solid sheet: Commercially available material, connecting yarn and mesh sheet material is PET
Mesh shape of substrate sheet (11, 13 in FIG. 1): hexagon, mesh size: a5 mm × b3 mm, sheet substrate interval 3 mm, basis weight of 3D solid sheet 300 g / m ²
Calcium aluminate a: amorphous calcium aluminate with CaO / Al ₂ O ₃ = 1.2: Blaine specific surface area 5900 cm ² / g
Calcium aluminate b: amorphous calcium aluminate with CaO / Al ₂ O ₃ = 1.5: Blaine specific surface area 5800 cm ² / g
Calcium aluminate d: amorphous calcium aluminate with CaO / Al ₂ O ₃ = 3.0: Blaine specific surface area 6000 cm ² / g
Calcium aluminate e: amorphous calcium aluminate with CaO / Al ₂ O ₃ = 3.3: Blaine specific surface area 5900 cm ² / g

(Test method)
Cured state: Evaluated 15 minutes after spraying. The case where it did not dent when the grass-proof sheet was pressed with a finger was evaluated as cured, and was marked as ◯. The case where it dents when it is pushed with a finger without hardening is set as x.
Permeation state: The ground side of the weedproof sheet was observed after 15 minutes. When water penetrated uniformly over the entire surface, it was marked as ◯, and when water did not penetrate evenly across the surface, it was marked as x.

  When the molar ratio of the calcium aluminate of the present embodiment is smaller than the lower limit, it is soft even after 15 minutes, and no improvement in strength is observed even after 28 days, and weeds are generated. When the calcium aluminate molar ratio exceeded the upper limit, the curing rate was too fast, and weeds were generated from the portion where water did not penetrate uniformly. On the other hand, within the molar ratio range of the calcium aluminate of the present embodiment, the cured state and the infiltrated state are also good, weeds are not generated, and an excellent herbicidal effect is obtained.

Using a three-dimensional solid sheet with a sheet base interval of 3 mm, the amount of γ-2CaO · SiO shown in Table 3 with respect to 100 parts by mass of calcium aluminate, 100 parts by mass of gypsum, 100 parts by mass of calcium aluminate c and gypsum _A herbicidal sheet was prepared in the same manner as in Example 1 except that ₂ was added to prepare a quick-hardening powder. The cured state, the infiltration state, the number of weeds, and the compressive strength after watering the weedproof sheet were measured. The results are shown in Table 3.

(Materials used)
γ-2CaO · SiO ₂ : 2 mol of calcium carbonate and 1 mol of silicon dioxide were mixed and pulverized, then calcined at 1450 ° C. for 3 hours in an electric furnace, taken out of the furnace, cooled by natural cooling, and synthesized. At this time, dusting was performed and the powder was pulverized to a brain specific surface area of 1,800 cm ² / g. This was further ground to a Blaine specific surface area of 4,000 cm ² / g.

(Test method)
Compressive strength: The hard hardening powder having the composition shown in Table 3 is filled in a 4 × 4 × 16 cm mold, and water is sprayed from the surface so that water is 20 parts by weight with respect to 100 parts by weight of the quick hardening powder. Solidified. One day later, the demolded and solidified test specimen was cured in air at a temperature of 20 ° C. and a humidity of 80% for 3 hours and 91 days, and measured according to JIS R 5201.

From Table 3, long-term strength can be improved by using γ-2CaO · SiO ₂ in combination.

  Example 1 with the exception that 100 mass parts of calcium aluminate c, 100 mass parts of gypsum, 100 mass parts of calcium aluminate and gypsum were added to the total amount of admixtures shown in Table 4 to prepare a quick-hardening powder. Similarly, a herbicidal sheet was prepared. Evaluation was performed in the same manner as in Example 3. The results are shown in Table 4.

(Materials used)
Fly ash: Commercially available product, manufactured by Tohoku Electric Power Industry Co., Ltd., JIS II type product, Blaine specific surface area: 3600 cm ² / g
Silica fume: Commercial product, Sakai Kogyo Co., Ltd. Trade name SF-R (Russian product), BET specific surface area: 19.5 m ² / g
Limestone fine powder: Commercial product, manufactured by Yoshizawa Lime Industry Co., Ltd., Blaine specific surface area: 5100 cm ² / g
Blast furnace slag fine powder: Commercially available product, manufactured by D.C., Inc., trade name: Fine Serament 20A, Blaine specific surface area: 4100 cm ² / g

(Test method)
BET specific surface area: Measured using “Macsorb HM model-1208” manufactured by MACSORB.

From Table 4, long-term strength development can be improved even if various admixtures other than γ-2CaO · SiO ₂ are used.

  Example 1 except that powder was prepared by adding 100 parts by weight of calcium aluminate c, 100 parts by weight of gypsum, 100 parts by weight of calcium aluminate and gypsum and adding fine aggregates in the amounts shown in Table 5 A weedproof sheet was prepared. Evaluation was performed in the same manner as in Example 3. The results are shown in Table 5.

(Materials used)
Fine aggregate: lime sand, maximum particle size 0.6mm

(Test method)
Maximum particle size of fine aggregate: Measured using several sieves with different nominal sizes as defined in JIS Z8801-1 "Sieving screen-Part 1: Metal mesh screen".

  From Table 5, it is possible to improve long-term strength development by using fine aggregate.

Experiment No. shown in Table 6 The size of the weed prevention sheet is scaled up to a sheet base interval of 3 mm, length of 1 m × width of 1 m, spread on 3 m ² of weeded ground, and water is set to 90 parts by mass with a watering device based on the quick hardening powder. Water was sprayed uniformly, and the state after about one year was observed. The results are shown in Table 6.

  This embodiment can provide the same construction as a conventional synthetic resin sheet even on a steep slope, and can provide a weedproof sheet that does not fly or break by wind and a construction method using the same.

  The weedproof sheet of this embodiment can be installed at a place where weed protection is desired even on a steep slope. In this embodiment, by spraying water from the surface of the herbicidal sheet, the filled quick-hardening powder is solidified, the sheet itself can be rigidized, and the effect of light shielding and strength development can be demonstrated for a long period of time. Demonstrate the herbicidal effect. Unlike the weedproof sheet made of synthetic resin, the weedproof sheet of the present embodiment does not fly or break with wind.

DESCRIPTION OF SYMBOLS 1 Three-dimensional sheet 11 1st mesh sheet 12 Connecting thread 13 2nd mesh sheet 14 Space | interval of sheet base material a Center distance in mesh long direction b Center distance in mesh short direction

Claims (6)

Calcium having a CaO / Al ₂ O ₃ (molar ratio) of 1.3 to _{3 in} a gap between a three-dimensional solid sheet in which two mesh sheets arranged so as to have an interval of 1 to 10 mm are connected by a connecting thread. A herbicidal sheet filled with a quick-hardening powder containing aluminate and gypsum and having a water-soluble film superimposed on one or both sides of the mesh sheet. Furthermore, Anti-weed sheet according to claim 1, further comprising a γ-2CaO · SiO _2. The herbicidal sheet according to claim 1 or 2, wherein the quick-hardening powder contains one or more selected from fly ash, siliceous fine powder, blast furnace slag and limestone fine powder. Furthermore, the weed prevention sheet | seat of any one of Claims 1-3 containing a fine aggregate. The herbicidal construction method using the weedproof sheet of any one of Claims 1-4. A herbicidal construction method in which the quick-hardening powder is solidified by sprinkling water on the surface after installing the weedproof sheet according to any one of claims 1 to 4 at a place where it is desired to prevent grass.

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