Herbicides and weed control methods

Abstract

To provide a herbicide and herbicidal method having no adverse effects on organisms of animals living in the surrounding area, having persistence and capable of suppressing the maintenance and operation cost.SOLUTION: A herbicide contains a silicone oligomer, a polyalkylene glycol with crosslinkable functional groups and a curing catalyst. Alternatively, a herbicide contains a silane coupling agent and a polyfunctional isocyanate compound. A herbicidal method for weeds includes the step of: removing weeds growing in gaps in concrete, mortar or asphalt; and filling the gaps in the concrete, mortar or asphalt with the herbicide.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a herbicide and a method for weeding weeds using the herbicide.

Background Art

[0002] Seeds of weeds fly into gaps such as joints, cracks in asphalt and concrete of roads, harbors, and buildings, and various vegetations are formed. It is common to remove developed vegetation by mowing. However, vegetation that develops in gaps often consists of perennial herbs, etc., and since the underground rhizomes remain after normal mowing, the vegetation recovers in a few months. Since it is difficult and laborious to remove the rhizomes, it is dealt with by regular weeding, but there is a problem that the maintenance cost increases. Furthermore, if weeding is not carried out from the underground part, the development of vegetation will further progress, causing deformation and breakage of roads and structures, and further promoting the growth of weeds.

[0003] Patent Document 1 discloses a herbicide composed of an acrylic coating or a urethane coating containing a physiologically active substance. Patent Document 2 discloses a paint having chemicals such as a herbicide and a repellent. The herbicide disclosed in Patent Document 1 and the paint disclosed in Patent Document 2 contain drugs such as physiologically active substances, and there are problems that there are concerns about adverse effects on the health of animals including humans and that the environmental load is large.

[0004] On the other hand, in recent years in Japan, it has become a social problem that specific alien organisms designated as specific alien organisms, such as Argentine ants, Argentine ants, and spider mites, and sanitary pests and agricultural pests inhabit the vegetation in gaps such as joints and cracks. Therefore, it is also required to prevent the breeding of specific alien organisms such as Argentine ants and pests through the removal of weeds.

Prior Art Documents

Patent Documents

[0005] [[ID= 30]]

Patent Document 1

[0006] The present invention aims to provide a herbicide and weed control method that do not have adverse effects on the living organisms of animals inhabiting the surrounding area, are sustainable, and can reduce maintenance costs. [Means for solving the problem]

[0007] As a result of various studies on various materials, the inventors of the present invention have found that using a composition containing a silicone oligomer, a polyalkylene glycol having a crosslinkable functional group, and a curing catalyst, or a composition containing a silane coupling agent and a polyfunctional isocyanate compound, results in a high herbicidal effect and sustained effect when impregnated into soil and plants, even though it does not contain physiologically active substances, and have completed the present invention.

[0008] In other words, the present invention relates to a herbicide containing a silicone oligomer, a polyalkylene glycol having a crosslinkable functional group, and a curing catalyst.

[0009] It is preferable that the crosslinkable functional group is a hydrolyzable silyl group.

[0010] Furthermore, the present invention relates to a herbicide containing a silane coupling agent and a polyfunctional isocyanate compound.

[0011] Furthermore, the present invention relates to a process for removing weeds growing in gaps in concrete, mortar, or asphalt, and The present invention relates to a method for controlling weeds, which includes the step of filling gaps in concrete, mortar, or asphalt with the aforementioned herbicide.

[0012] Furthermore, it is preferable to include a step of scattering aggregate in the gaps left by the cut weeds after the weed removal step.

[0013] Furthermore, it is preferable to include a step of spraying a water-absorbing agent after the step of removing weeds.

[0014] The gap is preferably a joint or a crack. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a herbicide and weed control method that do not contain physiologically active substances, or contain only extremely small amounts, and therefore have no adverse effects on the living organisms of humans, pets, and other animals, while having a high weed control effect. Furthermore, the herbicide and weed control method of the present invention can also prevent the proliferation of specific invasive species such as fire ants and various pests. [Modes for carrying out the invention]

[0016] The first herbicide of the present invention is characterized by containing a silicone oligomer, a polyoxyalkylene glycol having a crosslinkable functional group, and a curing catalyst. This herbicide has excellent quick-drying and penetrating properties, and exhibits rubber elasticity after curing. Therefore, the silicone oligomer impregnates the soil, weed seeds, and rhizomes of weeds that could not be completely removed with resin, thereby inhibiting weed growth. In addition, the polyoxyalkylene glycol having a crosslinkable functional group penetrates deeply into fine cracks and becomes elastic after curing, making it difficult for cracks to form and preventing the intrusion of weed root systems. Furthermore, by fixing the ground surface and soil, it can modify the environment to be unsuitable for plant growth by blocking sunlight, suppressing weed heading and sprouting, and blocking moisture. These three characteristics result in a highly sustained herbicidal effect. Moreover, since it does not contain physiologically active substances like herbicides, there is no problem of environmental burden.

[0017] The herbicide of the present invention is used by filling gaps in concrete, mortar, or asphalt where weeds grow. Examples of gaps include joints and cracks.

[0018] Weeds include grasses such as barnyard grass, goosegrass, wild oats, bermudagrass, and Japanese millet; those that thrive in joints such as sedges, plantain, dandelion, and longleaf groundsel; those that grow in groups along roadsides such as bluegrass, great ragweed, giant knotweed, pigweed, Japanese mugwort, and pampas grass; and in addition, woody plants such as Japanese holly, hogweed, Japanese wisteria, and false acacia.

[0019] Silicone oligomers are polymers of alkoxysilane and / or phenylalkoxysilane. Examples of alkoxysilane include monoalkoxytrimethylsilane, dialkoxydimethylsilane, trialkoxymethylsilane, and tetraalkoxysilane. Examples of phenylalkoxysilane include monoalkoxy triphenylsilane, dialkoxydiphenylsilane, and trialkoxyphenylsilane. Examples of alkoxy groups include methoxy group and ethoxy group.

[0020] The weight molecular weight of the silicone oligomer is preferably from 200 to 1000, more preferably from 200 to 500. If it is less than 200, the volatility increases, and if it exceeds 1000, the viscosity increases and the compatibility with other resins tends to decrease.

[0021] The viscosity of the silicone oligomer is preferably from 1 to 50 mm 2 / s at 25°C, more preferably from 1 to 10 mm 2 / s. If it is less than 1 mm 2 / s, the volatility increases, and if it exceeds 50 mm 2 / s, the viscosity increases and the compatibility with other resins tends to decrease.

[0022] The amount of SiO2 in the silicone oligomer is preferably from 45 to 70% by weight, more preferably from 45 to 65% by weight.

[0023] The silicone oligomer preferably has reactive functional groups. Examples of the reactive functional groups include an alkoxysilyl group, an epoxy group, a vinyl group, an alkyl group, and the like. From the viewpoint of reactivity, an alkoxysilyl group is preferable.

[0024] The content of the alkoxy group in the silicone oligomer is preferably 30 to 50% by weight, more preferably 40 to 50% by weight. If it is less than 30% by weight, the reactivity becomes low, and if it exceeds 50% by weight, the elasticity of the cured film tends to decrease.

[0025] Also, the content of the silicone oligomer is preferably 20 to 80% by weight, more preferably 50 to 70% by weight, in 100 parts by weight in total of the silicone oligomer and the polyalkylene glycol. If it is less than 20% by weight, it takes time to cure, and if it exceeds 80% by weight, the elasticity of the cured film tends not to be maintained.

[0026] Examples of the polyalkylene glycol having a crosslinkable functional group include polyethylene glycol, polypropylene glycol, polybutylene glycol, and the like. Among them, polypropylene glycol is preferable in terms of compatibility and water resistance.

[0027] Examples of the crosslinkable functional group include a methoxysilyl group, an ethoxysilyl group, a propoxysilyl group, and the like. From the viewpoint of reactivity, a crosslinkable silyl group such as a methoxysilyl group is preferable.

[0028] The weight molecular weight of the polyalkylene glycol is preferably 1000 to 10000, more preferably 5000 to 10000. If it is less than 1000, the elasticity is poor, and if it exceeds 10000, the viscosity tends to become too high.

[0029] The viscosity of the polyalkylene glycol is preferably 0.5 to 15 Pa·s, more preferably 5 to 15 Pa·s. If it is less than 0.5 Pa·s, it tends to become brittle, and if it exceeds 15 Pa·s, the viscosity tends to increase.

[0030] Examples of curing catalysts include titanium-based and tin-based catalysts. Examples of titanium-based curing catalysts include alkoxytitanium compounds such as tetrabutoxytitanium and tetraisopropoxytitanium, while examples of tin-based catalysts include tin compounds such as dibutyldilauryl tin. Among these, tetra-n-butoxytitanium is preferred in terms of curability and environmental impact.

[0031] The curing catalyst content is preferably 0.2 to 2 parts by weight, and more preferably 0.5 to 1.5 parts by weight, per 100 parts by weight of the total of the silicone oligomer and the polyalkylene glycol having crosslinkable functional groups. If the content is less than 0.2 parts by weight, curing tends to be too slow, and if it exceeds 2 parts by weight, the water resistance of the effective coating tends to decrease.

[0032] Furthermore, the second herbicide of the present invention is characterized by containing a silane coupling agent and a polyfunctional isocyanate compound. This herbicide has low viscosity, excellent penetration, and rubber elasticity after hardening. Therefore, the silane coupling agent and the polyfunctional isocyanate compound impregnate the soil, weed seeds, and the rhizomes of weeds that could not be completely removed, thereby inhibiting weed growth. This resin impregnation effect is higher than that of the first herbicide. In addition, the silane coupling agent and the polyfunctional isocyanate compound penetrate deeply into fine cracks and become elastic after hardening, making it difficult for cracks to form and preventing root penetration. Furthermore, by fixing the ground surface and soil, it can modify the environment to be unsuitable for plant growth by blocking sunlight, suppressing weed heading and sprouting, and blocking moisture. These three characteristics result in a high herbicidal effect. Moreover, since it does not contain physiologically active substances like the herbicides disclosed in Patent Documents 1 and 2, there is no problem of burden on the surrounding environment.

[0033] Silane coupling agents are compounds that have other functional groups besides alkoxysilyl groups, such as epoxy groups, amino groups, vinyl groups, and acryloyl groups. Examples include epoxysilanes, aminosilanes, vinylsilanes, and acryloylsilanes.

[0034] Examples of polyfunctional isocyanate compounds include condensates of hexamethylene diisocyanate, pentamethylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and isophorone diisocyanate.

[0035] The content of the polyfunctional isocyanate compound is preferably 50 to 500 parts by weight, and more preferably 70 to 250 parts by weight, per 100 parts by weight of the silane coupling agent. If the content is less than 50 parts by weight, curing will be insufficient, and if it exceeds 500 parts by weight, there will be too many isocyanate groups, which tends to also result in curing failure.

[0036] The aforementioned curing catalyst can be used. The curing catalyst content is preferably 0.1 to 2 parts by weight, and more preferably 0.2 to 1 part by weight, per 100 parts by weight of the total of the silane coupling agent and the polyfunctional isocyanate compound. If the content is less than 0.1 parts by weight, curing tends to be too slow, and if it exceeds 2 parts by weight, the water resistance of the effective coating tends to decrease.

[0037] In addition to the silicone oligomer, the polyalkylene glycol having a crosslinkable functional group, and the curing catalyst, the herbicide of the present invention may contain known additives. Examples of such additives include organic solvents, plasticizers, fillers such as calcium carbonate and talc, inorganic compounds such as titanium dioxide, and compatible low-molecular-weight resins.

[0038] The herbicide of this invention may incorporate silica sand, volcanic ash soil, charcoal powder, wood powder or wood chips, bamboo chips, rubber powder, quicklime, and various pigments as aggregates to improve application efficiency, weather resistance, and aesthetics. Using wood-derived aggregates improves elasticity and provides environmental benefits such as carbon sequestration and recycling in the soil. Furthermore, using quicklime generates high temperatures in the soil, which can provide insecticidal and herbicidal effects.

[0039] Furthermore, the weed control method of the present invention is characterized by comprising the steps of: removing weeds growing in gaps in concrete, mortar, or asphalt; and filling the gaps in concrete, mortar, or asphalt with the herbicide.

[0040] Examples of places where gaps exist in concrete, mortar, or asphalt include not only buildings (including rooftops), but also port container yards, bridges, sidewalks, embankments, pedestrian bridges, agricultural waterways, and walkways around tanks. These gaps include joints, cracks, and fissures. It is preferable to use this product in places where the use of herbicides and insecticides containing physiologically active substances is restricted, such as schools, food factories, and medical facilities.

[0041] In the process of removing weeds growing in cracks in concrete, mortar, or asphalt, specific methods for removing weeds include pulling them out, cutting them with a sickle or grinder, spraying them with hot water, and burning them with a burner. These methods can be used in combination; for example, pulling out or cutting the weeds with a sickle or grinder can be done after spraying them with hot water or burning them with a burner. After spraying with hot water or burning, the weeds can be easily removed. The weed removal process can be carried out regardless of the season.

[0042] In the method of spraying hot water, it is preferable to spray so that the temperature within a few centimeters of the ground is preferably 60°C, and more preferably 70°C or higher. Hot water penetrates deeper than incineration with a burner, etc., and can enhance the effect of killing plants by heat.

[0043] Furthermore, it is preferable to include a step of scattering aggregate in the gaps left by the weeds after the weed removal step. Examples of aggregate include silica sand, volcanic ash soil, charcoal powder, wood powder or wood chips, bamboo chips, rubber powder, quicklime, and various pigments.

[0044] Furthermore, it is preferable to include a step of spraying a water-absorbing agent after the weed removal step. By spraying the water-absorbing agent, weeds that could not be sufficiently removed can be killed. This step creates a layer of dead plants. Examples of water-absorbing agents include water-absorbing resins such as polyacrylic acid, polyacrylate salts, carboxymethylcellulose salts and their reactions.

[0045] For immediate effectiveness, it is preferable to spray salt or acid along with a water-absorbing agent before injecting the herbicide. Examples of salt include sodium chloride, potassium chloride, and sodium bicarbonate (baking soda), but soil from tidal flats or sandy beaches containing salt can also be used. Examples of acid include citric acid and acetic acid. In coastal areas such as container yards, salt spraying is not always necessary as surrounding seawater is drawn in. From the standpoint of workability, it is preferable to spray salt or acid in a solid state. In addition to solid salt or acid, volcanic ash or rice paddy soil that has been absorbed with salt or acid and dried can also be used.

[0046] In the process of filling gaps in concrete, mortar, or asphalt with herbicide, the herbicide of the present invention is poured into the gaps using a tube or the like. If the polyalkylene glycol has moisture-curing functional groups, it hardens at room temperature due to moisture in the air. The hardening time is 2 to 4 hours, and by the time hardening is complete, it has exerted an impregnation effect on the soil, weed rhizomes, and seeds. To further enhance penetration, it is necessary to delay the effect time, and the amount of hardening agent or hardening accelerator added can be adjusted. [Examples]

[0047] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples.

[0048] The materials used in the examples and comparative examples are shown below.

[0049] <<A herbicide containing a silicone oligomer, a polyalkylene glycol having a crosslinkable functional group, and a curing catalyst.>> Silicone oligomer: KC-89S (manufactured by Shin-Etsu Chemical Co., Ltd.), Organic substituent: Methyl group, Alkoxy group: Methoxy group, Viscosity (25℃): 5mm 2 / s, alkoxy group content: 45% by mass, SiO2 content: 59% by mass Polyalkylene glycol: MS Polymer S-303H (manufactured by Kaneka Corporation), viscosity: 8 Pa·s Curing catalyst 1: Tetra-n-butoxytitanium (manufactured by Fujifilm Wako Pure Chemical Corporation)

[0050] <<Herbicides containing silane coupling agents and polyfunctional isocyanate compounds>> Silane coupling agent: 3-Glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) Hexamethylene diisocyanate isocyanurate: D-170N (manufactured by Mitsui Chemicals, Inc.) Curing catalyst 2: Dibutyltin dilaurate (manufactured by Fujifilm Wako Pure Chemical Corporation)

[0051] Examples 1-4 and Comparative Example 1 The silicone oligomer, polyalkylene glycol, and curing catalyst 1 were placed in a beaker in the proportions shown in Table 1 and stirred thoroughly with a stirrer for 30 minutes to obtain a herbicide. Similarly, the silane coupling agent, isocyanate compound, and curing catalyst 2 were placed in a beaker in the proportions shown in Table 2 and stirred thoroughly with a stirrer for 30 minutes to obtain another herbicide. The quick-drying, penetrating, and elastic properties of the obtained herbicides were evaluated as follows. The results are shown in Tables 1 and 2.

[0052] <Quick drying> 10g of paint was dropped onto a 10cm x 10cm glass plate and left to stand. The drying process was checked every hour by touching it with a finger, and the time until the paint no longer stuck to the finger was considered the drying time.

[0053] <Permeability> A 5cm x 5cm x 2cm urethane sponge (Urethane No. 1 1U61 (manufactured by Fuji Rubber Industries Co., Ltd.)) was covered with 10g of paint from above and left for one week. After that, it was cut in half and the depth to which the paint had penetrated was measured.

[0054] <Elasticity> I poured 20g of paint into a 100cc beaker containing 20g of coarse sand and left it for a week to harden. I then pressed the hardened material with my hand to check its elasticity. ○: When pressed from above with a finger, a rubbery elasticity was observed. △: When pressed from above with a hand, it was hard, and when considerable force was applied, it dented slightly. ×: Does not deform even when pressed down on with a hand from above.

[0055] [Table 1]

[0056] [Table 2]

[0057] <Herbicide 1> On a roadside guardrail overgrown with weeds, hot water was sprayed onto the weeds growing in the gaps between the concrete and asphalt. After one hour, the weeds were cut. Then, the herbicides prepared in Examples 1-4 were filled into the gaps. Even after one year, no weeds grew in the treated area. Therefore, it was found that the herbicide of the present invention has excellent elasticity, quick-drying properties, and penetration, and is highly effective in weed control.

[0058] <Herbicidal property 2> In a 10-meter section of road asphalt joints overgrown with weeds, hot water was sprayed onto the weeds growing in the gaps, and after one hour, the weeds were mowed. Silica sand No. 5 was then laid in the gaps where the weeds had been cut. On top of the silica sand No. 5, the herbicide prepared in Example 2 was filled at 10 cm intervals, and the area was alternated between areas with and without the herbicide. The areas without the herbicide served as the control. In addition, the herbicide prepared in Example 4 was used instead of the herbicide prepared in Example 2, and the same procedure was followed.

[0059] The filled areas were observed after 100, 200, and 500 days, and the percentage of blocks where weeds grew was determined. The results are shown in Table 3.

[0060] [Table 3]

[0061] When the herbicides prepared in Example 2 or 4 were applied, almost no weeds grew even after 500 days.

Claims

1. A herbicide containing a silicone oligomer, a polyalkylene glycol having a crosslinkable functional group, and a curing catalyst.

2. The herbicide according to claim 1, wherein the crosslinking functional group is a hydrolyzable silyl group.

3. A method for controlling weeds, comprising the steps of: removing weeds growing in gaps in concrete, mortar, or asphalt; and filling the gaps in concrete, mortar, or asphalt with the herbicide described in claim 1 or 2.

4. Furthermore, the method for removing weeds according to claim 3, further comprising the step of scattering aggregate in the gaps left by the cut weeds after the step of removing the weeds.

5. Furthermore, the weeding method according to claim 3 or 4, further comprising the step of spraying a water-absorbing agent after the step of weeding.

6. A method for controlling weeds according to any one of claims 3 to 5, wherein the gap is a joint or a crack.

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