JP6722509B2 - Weed control material and method of using it - Google Patents

Description

TECHNICAL FIELD The present invention relates to a weed control material that suppresses the growth of weeds and a method of using the same while imparting conductivity to electric facilities such as railways, roads, steel towers, and animal protection fences.

There is a problem that electricity is short-circuited when weeds grow around electric facilities such as railways, roads, steel towers, and animal protection fences and they come into contact with electric wires.
Therefore, frequent mowing and spraying of herbicides were necessary. In particular, since a great deal of labor is required for cutting grass, a method of spraying a herbicide is generally used.
However, the spraying of herbicides is not a drastic measure because it requires frequent spraying only by killing the grass. In addition, a method of sprinkling a weed control material containing cement to sprinkle water to cover the ground has also been proposed, but there is a problem that it has a bad influence on a place where electrical resistance is high and conductivity is required. .. For example, in an animal protection fence, electricity does not flow to an animal unless there is a constant electric conduction between the electric wire, the ground, and the animal through the ground. As a guideline for driving away wild boars and other harmful animals, the Wakayama Prefectural Agricultural Damage Prevention Measures Manual states that a voltage of 3,500V or higher is required at the point of installing electric fences. Further, since the weed-controlling material containing cement has high alkalinity by containing cement and further contains hexavalent chromium, there is a problem in environmental impact.

Further, a weed suppressor and a method of spraying a cement-free magnesium oxide-based solidifying material or mixing it with soil and sprinkling water to solidify and suppress weeds have been proposed. (Patent Documents 1, 2, 3)
In Patent Document 1, a weed breeding preventive material containing magnesium oxide and blast furnace slag as main components is mixed with soil on the ground surface, compacted by compaction, and sprinkled with water, which requires labor for construction. In addition, since the initial strength development is low, there is a problem that it is easily washed away by rainfall after construction, the effect of weeding in the breeding season is easily reduced, and the conductivity is low.
Since Patent Documents 2 and 3 are also magnesium oxide-based solidifying materials similar to those of Patent Document 1, there is a problem that the effect of suppressing weeds during the breeding season is low.
Patent Document 4 is a weed-preventing layer containing a soil material, a cement-based solidifying material, and an aggregating agent as a main component, but as described above, the cement-containing material has high alkalinity and further contains hexavalent chromium. Therefore, there was a problem in terms of environmental impact.
Patent Documents 5, 6, and 7 propose a grass-proof sheet having conductivity. However, the weed-preventing sheet has a problem in terms of aesthetics, the effect of weeding is reduced, and periodical replacement requires a great deal of labor.

JP, 2003-47388, A JP, 2007-330114, A JP, 2014-51849, A JP, 2011-239748, A JP 2012-60948 A Utility model registration No. 3185209 JP, 2004-176197, A

The present invention provides a weed preventive material which can be imparted with conductivity, can reduce the labor of cutting grass, and can ensure the conductivity and the lasting effect of weed control, and a method of using the same.

That is, the present invention provides (1) a weed proofing agent containing calcium aluminate, soil and an alkali metal salt, (2) a weed proofing agent of (1) containing gypsum, and (3) calcium. The aluminate contains the weed proofing material of (1) or (2) in which the CaO/Al ₂ O ₃ molar ratio is 1.0 to ₃ and the impurities are 15 mass% or less, and (4) further contains calcium silicate. (1) to (3) any of the weed control material, (5) (1) to (4) any of the weed control material is spread on the ground, the use of a weed control material sprayed on it Method, (6) A method of using the weed-proofing material, which comprises kneading the weed-proofing material of any one of (1) to (4) with water and spreading it on the ground to cover it.

INDUSTRIAL APPLICABILITY The weed proof material of the present invention exerts effects such as imparting conductivity, reducing the labor of mowing, and ensuring the conductivity and the sustainability of the weed control effect.

Hereinafter, the present invention will be described in detail.

The calcium aluminate used in the present invention contains CaO and Al ₂ O ₃ which are obtained by mixing a calcia raw material and an alumina raw material and firing them in a kiln or melting and cooling in an electric furnace as main components. It is a generic term for substances having hydration activity, and it can be used in either crystalline or amorphous form, and has a fast curing time and high initial strength development. Typical examples of calcium aluminate include alumina cement, and commercially available ones can be used. For example, alumina cement No. 1 and alumina cement No. 2 can be used. Amorphous calcium aluminate, which has been hardened in a shorter time than alumina cement and has a high initial strength development after that, is preferably quenched and then cooled, and a molar ratio of CaO and Al ₂ O ₃ (CaO/Al ₂ O 1.0-3.0 are preferable and, as for ₃ molar ratio, 1.7-2.5 are more preferable. In the case of 1.0 to 1.7, it is possible to further shorten the hardening time and enhance the initial strength development by adding cement, slaked lime and quick lime.
Furthermore, in the present invention, the impurities other than CaO and Al ₂ O ₃ contained in the calcium aluminate are preferably 15% by mass or less from the viewpoint of the initial strength development property, and more preferably 10% by mass or less. .. If it exceeds 15% by mass, it will take time to cure, and it will not harden at low temperatures, and the weed-preventing effect may be low. Silicon oxide is a typical example of impurities, and in addition, alkali metal oxides, alkaline earth metal oxides, titanium oxide, iron oxides, alkali metal halides, alkaline earth metal halides, alkali metal sulfates, and alkaline earth metals. There are some metal sulfates substituted with CaO or Al ₂ O ₃ but there is no particular limitation.

The vitrification rate of calcium aluminate is preferably 70% or more, and more preferably 90% or more in terms of reaction activity. If it is 70% or less, the initial strength developability may decrease. From the viewpoint of reaction activity, the vitrification rate of calcium aluminate is preferably 70% or more, more preferably 90% or more. 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, and then heated at 1000° C. for 2 hours and then gradually cooled at a cooling rate of 1 to 10° C./min. The main peak area S ₀ of the crystalline mineral after heating by the powder X-ray diffraction method is determined, and the vitrification rate χ is calculated using the following equation using the values of S ₀ and S. Vitrification rate χ (%) = 100 x (1-S/S ₀ )
The particle size of the calcium aluminate, in terms of initial strength development is preferably more than Blaine specific surface area ^{3000cm 2 / g, 5000cm 2 /} g or more is more preferable. If it is less than 3000 cm ² /g, the curing time may be long and the initial strength development may be deteriorated.

The alkali metal salt used in the present invention is not particularly limited as long as the conductivity can be secured, and it is possible to use a powdery one or a liquid one.
Li, Na, and K are preferable as the cation because they are inexpensive and easily available. These hydroxides, hydroxides, bicarbonates, carbonates, nitrates, chlorides, nitrites, silicates, phosphates, sulfates, sulfites, bisulfites, thiosulfates, thiocyanates Examples thereof include salts and the like, and although not particularly limited, chloride salts and sulfates are more preferable because they do not cause strength reduction and do not increase pH.
The amount of alkali metal salt used is preferably 0.2 to 20 parts by mass, and more preferably 1 to 10 parts by mass, relative to 100 parts by mass of calcium aluminate. If it is less than 0.2 parts by mass, the effect of improving conductivity may be small, and if it exceeds 20 parts by mass, it is uneconomical.

As the gypsum used in the present invention, hemihydrate gypsum and anhydrous gypsum can be used, and anhydrous gypsum is preferable from the viewpoint of strength development, and anhydrous gypsum by-product of hydrofluoric acid and natural anhydrous gypsum can be used. The pH of the gypsum when immersed in water is preferably from weak alkali to pH 8 or less to acidic. When the pH is high, the solubility of the gypsum component becomes high, which may hinder the initial strength development. The pH referred to here is the pH of a dilute slurry of gypsum/ion-exchanged water=1 g/100 g at 20° C. measured using an ion-exchange electrode or the like.
The particle size of the gypsum, preferably 3000 cm ² / g or more in Blaine specific surface area value, from the viewpoint of the 5000 cm ² / g or higher initial strength development, the proper work time is obtained.
The amount of gypsum used is not particularly limited, but is preferably 50 to 250 parts by mass with respect to 100 parts by mass of calcium aluminate. If the amount is less than 50 parts by mass, the strength development may be deteriorated and the weed control effect may be low. If it exceeds 250 parts by mass, the strength developing property may decrease, and the weed-preventing effect may be low.

In the present invention, calcium silicate can be used for the purpose of enhancing strength.
Calcium silicate includes 3CaO·SiO ₂ and 2CaO·SiO ₂ and is not particularly limited, but γ-2CaO·SiO ₂ absorbs carbon dioxide in the atmosphere to densify the tissue and has a weed-preventing effect. Most preferred because it is excellent.
γ-2CaO · SiO ₂ is different among the compounds represented by 2CaO · SiO _2, is what is known as low-temperature phase, the α-2CaO · SiO ₂ and β-2CaO · SiO ₂ is a high temperature phase It is a thing. All of these compounds are 2CaO.SiO ₂ and have the same chemical composition but different crystal structures. 2CaO · SiO ₂ present in the cement clinker is a β-2CaO · SiO _2. It has been found that β-2CaO·SiO ₂ has hydraulic properties, but γ-2CaO·SiO ₂ in the present invention does not have hydraulic properties, but has the property of absorbing carbon dioxide in the atmosphere and hardening.
The particle size of the γ-2CaO · SiO ₂ is not particularly limited but is preferably 3000 cm ² / g or more in Blaine specific surface area value, 4,000~8,000cm ² / g is more preferable. When the Blaine specific surface area value is less than 3,000 cm ² /g, carbon dioxide in the air is absorbed and the reaction is not sufficient, and crack resistance may not be sufficiently obtained. Even if it exceeds 8,000 cm ² /g, further enhancement of the effect cannot be expected.
The amount of calcium silicate used is not particularly limited, but is preferably 10 to 60 parts by mass with respect to 100 parts by mass of calcium aluminate and gypsum in total. If it is less than 10 parts by mass, the strength may be low. If it exceeds 60 parts by mass, further improvement of the effect cannot be expected.

In the herbicide of the present invention, the proportion of soil is not particularly limited with respect to 100 parts by mass of calcium aluminate and gypsum in total, but usually 100 to 1000 parts by mass is preferable, and 200 to 800 parts by mass. Parts are more preferred. When the amount of soil is less than 100 parts by mass, strength development is high, but it is economically unfavorable. If it exceeds 1000 parts by mass, the strength is low and the grass-controlling effect may not be obtained.

The soil used in the present invention is not particularly limited as long as it contains any one kind or two or more kinds of gravel, sand, gravel and clay. Sandy soil such as mountain sand, river sand, sea sand, silty soil, clay soil, residual soil generated from construction, heavy aggregate, lightweight aggregate, regenerated aggregate, and soil at the place where weed control is used as it is Any of these can be used. Generally, natural sand such as Masago soil, Akadama soil, Kanuma soil, mountain sand, sea sand, and crushed sand have stable quality, and are more preferable.

The blending amount of water is preferably 5 to 100 parts by mass with respect to 100 parts by mass of the total weed proofing material of the present invention. If it is less than 5 parts by mass, mixing may be difficult, and if it exceeds 100 parts by mass, strength may not be obtained.

In the present invention, the coagulation modifier can be used within the scope of the present invention. The setting modifier is not particularly limited as long as it accelerates or delays the setting of cement. Specifically, one or more of oxycarboxylic acid or a salt thereof, phosphoric acid or a salt thereof, dextrin, sucrose, polyacrylic acid or a salt thereof, a water-reducing agent, a high-performance water-reducing agent, and the like, the object of the present invention. It is possible to use it in the range which does not substantially inhibit.

In the present invention, low pH solidifying materials such as magnesium oxide, wood chips, bulking materials such as rice husks, etc., various portland cements, calcium hydroxide, calcium chloride, fine limestone powder, fly ash, kaolin, carbon, shirasu , Admixtures such as diatomaceous earth and silica fume, foaming agents, defoaming agents, thickeners, rust preventives, antifreeze agents, water reducing agents, superplasticizers, polymers, clay minerals such as bentonite, anion exchangers such as hydrotalcite It is possible to use one kind or two or more kinds of colorants, etc. within a range not substantially impairing the object of the present invention.

In the present invention, the mixing method of each material is not particularly limited, and the respective materials may be mixed at the time of construction, and part or all of them may be mixed in advance. In terms of quality, it is better to mix with water and mix water on site. When premixed, the soil is preferably dry.

As the mixing device, any existing device can be used, and for example, a tilting barrel mixer, an omni mixer, a biaxial forced mixer, a Henschel mixer, a V-type mixer, and a Nauta mixer can be used.

In the present invention, a method of covering the ground weeds with a grass mower or the like to a depth of about 1 cm or less, removing the weeds, laying a weed-proofing material, and sprinkling with water. Further, there is a method of spraying with a mixed herbicide, and it is more preferable to mow the grass and then spray the herbicide before covering.

When the grass is spread over the ground, and the surface of the grass is solidified by coating with water, the grass is preferably spread over the ground and then sprayed with a watering can or the like. The thickness to be spread is not particularly limited, and a thickness of 1 to 3 cm at the convex portion of the ground is preferable. If it is 1 cm or less, it may be difficult to cover the entire surface, and the weed-preventing effect may be lowered. If it is 3 cm or more, the weed-preventing effect is high but the material cost is high, which is not preferable because it requires a lot of labor.

The weed proofing material of the present invention or laying on the ground excluding the soil of the weed proofing material of the present invention is mixed and stirred with a backhoe or a stabilizer when mixed and stirred with the ground soil. It is possible to It is also possible to make a hard ground by further rolling.

Hereinafter, it demonstrates based on the experiment example of this invention.

"Experimental example 1"
To 100 parts by mass of calcium aluminate shown in Table 1, 100 parts by mass of gypsum and the type and amount of alkali metal salt shown in Table 1 were blended. Furthermore, the soil is set to 500 parts by mass with respect to the total of 100 parts by mass of calcium aluminate and gypsum, and 0.3 parts by mass of sodium citrate as a coagulation regulator is added to 100 parts by mass of calcium aluminate, gypsum and soil. Then, a part of the herbicide was prepared. After laying this herbicide on a mold, 15 parts by mass of water was sprinkled on 100 parts by mass of calcium aluminate, gypsum and soil to prepare a test body. The pH, hexavalent chromium, weed-preventing effect, and voltage of this test body were measured.
For comparison, mortar and magnesia-based solidifying agent using ordinary cement were prepared (Experiment No. 1-14, 1-15). The mortar is mixed by laying dry mortar (standard) made by Cement Association (standard) and standard Portland cement at a mass ratio of 3/1 on the formwork, and water is sprinkled so that the water cement ratio becomes 50 mass %. Then, a herbicide was prepared. The magnesia-based solidifying material is laid on a formwork in which 600 parts by mass of soil is mixed with 100 parts by mass of commercially available magnesium oxide obtained by burning magnesium produced in China, and 20 parts by mass of water is sprinkled to form a herbicide. Prepared. Furthermore, weeds were not laid and measurements were taken on the ground as it was (Experiment No. 1-16). The results are also shown in Table 1.

<Materials used>
Calcium aluminate: CaO/Al ₂ O ₃ molar ratio of calcium carbonate and aluminum oxide was changed, silica was added, and melted at 1650° C. and rapidly cooled. Vitrification rate 97%, Blaine specific surface area value 5000 cm ² did. Impurity was silica, and its content was changed and adjusted.
Alkali metal salt A: sodium sulfate, primary reagent alkali metal salt B: potassium chloride, primary reagent gypsum: natural anhydrous gypsum, Blaine specific surface area value 5000 cm ² /g
Soil: Lime sand from Niigata prefecture, 5mm sieve alumina cement: Alumina cement No. 1, Denka Coagulation modifier: Anhydrous sodium citrate, Iwata Chemical Co., Ltd. Water: Tap water Ordinary cement: Ordinary Portland cement, Denka Sand: (Company) Standard sand made by Cement Association Magnesia-based solidifying material: Commercially available magnesium oxide obtained by firing Chinese magnesium

<Measurement method>
pH: For each herbicide, a 4×4×16 cm specimen was prepared in accordance with JIS R 5201 in an environment of 20° C. and 60% relative humidity. The curing method was air-drying curing in an environment of 20° C. and 60% relative humidity. The specimen at the age of 28 days was crushed and stirred with 100 times pure water for 30 minutes, and the pH of the supernatant was measured.
Hexavalent chromium elution amount: For each herbicide, after making test specimens in the environment of 20°C and relative humidity of 60% in the same manner as in the pH test, test specimens at the age of 7 days were designated as Environmental Agency Notification No. 46. It measured based on the method.
Weed control test: Weeds overgrown under a protective fence are cut to a length of 0.5 cm or less with a mower in advance, and the fields are cultivated with a cultivator. 40 g/m ² of the mixture of ryegrass was sprinkled, which was stepped on with a foot and rolled. After laying each herbicide on the foundation surface uniformly with a thickness of 3 cm, a width of 1 m, and a length of 15 m, 15 parts by mass of water was sprinkled on 100 parts by mass of each weed suppressor after 60 days. After 180 days, the average number of grasses per 1 m ² grown from the surface of the grass was measured.
Voltage test: Supports were erected at intervals of 5 m in a section of 15 m, and four electric wires were installed at a height of 15 cm from the ground, up to 60 cm. Next, we installed the electric pastor on the pole, connected the electric pastor to the electric wire, grounded it, and installed the electric fence. Then, the weed-proof material was applied similarly to the weed-proof test, and the voltage after 60 days and 180 days was measured with a voltmeter.

From Table 1, it can be seen that the weed proofing material of the present invention is excellent in weed proofing property and conductivity, further low in pH and leaching amount of hexavalent chromium, and is excellent in environmental influence.

"Experimental example 2"
Using the calcium aluminate and alkali metal salt of Experiment No. 1-3 of Experimental Example 1, the ratio of calcium aluminate and gypsum was changed at the ratio shown in Table 2, and the total amount of calcium aluminate and gypsum was changed to 100 parts by mass. On the other hand, the same procedure as in Experimental Example 1 was performed except that the proportion of soil was changed. The results are also shown in Table 2.

<Materials used>
Calcium aluminate: CaO/Al ₂ O ₃ molar ratio 2.2, vitrification rate 97%, Blaine specific surface area value 5000 cm ²
Alkali metal salt A: Sodium sulfate, first-class reagent

From Table 2, it can be seen that the weed control material of the present invention is excellent in weed control and conductivity.

"Experimental example 3"
The experiments were carried out in the same manner as in Experimental Example 1 except that the calcium silicate was mixed in the proportions shown in Table 4 for the weed control materials of Experiment Nos. 1-3. The results are also shown in Table 3.

<Materials used>
Calcium aluminate: CaO/Al ₂ O ₃ molar ratio 2.2, vitrification rate 97%, Blaine specific surface area value 5000 cm ²
Calcium silicate: 3CaO.SiO ₂ 3 mol of calcium carbonate as a reagent and 1 mol of silicon dioxide were mixed and pulverized, and then calcined in an electric furnace to synthesize. Blaine specific surface area value of 1800 cm ² /g.
Calcium silicate B: β-2CaO · SiO ₂ after the calcium carbonate 2 moles and silicon 1 mole dioxide reagent were mixed and pulverized, and then calcined in an electric furnace synthesis. Blaine specific surface area value of 1800 cm ² /g.
Calcium silicate c: 2 mol of calcium carbonate of γ-2CaO.SiO ₂ reagent and 1 mol of silicon dioxide were mixed and pulverized, and then calcined in an electric furnace to synthesize. Blaine specific surface area value of 1800 cm ² /g.
Water: tap water

It can be seen from Table 3 that the grass control material of the present invention is more excellent in the effect of suppressing turf while ensuring conductivity when calcium silicate is used in combination.

"Experimental example 4"
For each of the herbicides of Experiment Nos. 3-7, 3-8, and 3-9 of Experimental Example 3, 15 parts by mass of water was added to 100 parts by mass of calcium aluminate, gypsum, calcium silicate, and coagulation modifier. The experiment was performed in the same manner as in Experimental Example 3 except that the mixture was added to the omni mixer and kneaded, and the mixture was laid on the formwork or foundation surface instead of watering (Experiments No. 4-3, 4-4, 4-5).
For comparison, the mortar (experiment No. 1-14) and the magnesia-based solidifying material (experiment No. 1-15) using the ordinary cement used in Experiment 1 are the same as the amount of water used in Experiment 1, respectively. The experiment was carried out in the same manner as in Experimental Example 3 (Experiment Nos. 4-1 and 4-2) except that instead of sprinkling water, a kneaded mixture was laid on the formwork or foundation surface. The results are also shown in Table 4.

It can be seen from Table 4 that the weed proofing material of the present invention is excellent in the weed proofing effect and the conductivity even when the kneaded mixture is laid.

By the weed control material and the method of using the same of the present invention, conductivity is imparted, the labor of mowing can be reduced, and the conductivity and the effect of ensuring the sustainability of the weed control effect can be obtained. Therefore, railways, roads, steel towers, It can be applied around electric facilities such as animal protection fences and is widely used in the fields of agriculture and construction.

Claims (6)

A herbicide containing calcium aluminate, gypsum, soil and an alkali metal salt ,
The amount of gypsum is 50 to 250 parts by mass and the amount of alkali metal salt is 0.2 to 20 parts by mass with respect to 100 parts by mass of calcium aluminate,
The amount of soil is 100 to 1000 parts by mass with respect to 100 parts by mass of calcium aluminate and gypsum in total.
Weed control material characterized in that The weed proofing material according to claim 1 , wherein the calcium aluminate has a CaO/Al ₂ O ₃ molar ratio of 1.0 to ₃ and impurities of 15 mass% or less. Furthermore, the weed proofing material according to claim 1 or 2 containing calcium silicate. Calcium silicate is γ-2CaO・SiO ₂ The weed control material according to claim 3, comprising: A method of using a weed-proofing material, which comprises spreading the weed-proofing material according to any one of claims 1 to 4 on the ground and sprinkling water on it. A method of using a weed-proofing material, which comprises kneading the weed-proofing material according to any one of claims 1 to 4 with water and spreading it on the ground to cover it.