JP2000212010A - Antimicrobial composition collapsible with time for application in soil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antimicrobial composition collapsible with time for application in soil, and having extremely raised safety at the time of production, preservation, and application in the soil, and further until the beginning of farm working after the application of the composition. SOLUTION: This antimicrobial composition is obtained by coating a solid antimicrobial agent consisting of an alkali metal salt and/or an alkaline earth metal salt of chlorous acid, and a solid diluent comprising inorganic salts having non-hygroscopic property and not containing a reducible compound, and/or neutral to alkaline, and refined and dried mineral products having <=0.001 wt.% metal content, and <=0.1 wt.% content of a heavy metal oxide, with a coating agent collapsible with time. The coating agent contains a silicone oligomer or the silicone polymer obtained by arbitrarily combining a bifunctional or trifunctional silane coupling agent with a trifunctional or tetrafunctional alkoxysilane, and co-hydrolyzing the combined materials.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fungicide for soil application, and more particularly to a fungicide for soil application coated with a time-disintegrable coating, which is manufactured, stored, and applied to soil. The present invention also relates to a very safe fungicide composition which can ensure the safety up to the point of application, and can also adjust the time for expressing bactericidal properties after application.

[0002]

2. Description of the Related Art Conventionally, as a method for disinfecting soil, a method using methyl bromide, which has excellent herbicidal properties and is also effective against filamentous fungi, nematicides, bacteria and viruses, has been widely practiced. . However, methyl bromide has a large ozone depletion potential, and is scheduled to be completely abolished in Japan in 2005 by an international treaty. Under these circumstances, as an alternative to the disinfection method using methyl bromide, use of chlorine dioxide water, blowing of chlorine dioxide gas, bactericidal, fungicidal and nematicidal by stabilized chlorine dioxide, and killing by sodium chlorite Insects have been suggested.

[0003]

However, such a conventional soil disinfection method has a low dispersibility to soil and cannot produce chlorine dioxide which is effective for sterilization and insecticide. Insecticides cannot be performed, and other alternatives related to existing agricultural chemicals or combinations thereof have been proposed, but their disinfection and disinfection effects are not as satisfactory as almighty like methyl bromide. There were challenges. Attempts have also been made to apply an alkali metal salt of chlorite and a solid acid as a composition, but when the chlorite is brought close to the acid, chlorine dioxide gas is instantaneously generated, and in some cases, an explosion occurs. There is also danger. Furthermore, alkali metal salts and alkaline earth metal salts of chlorous acid are associated with many dangers such as fire, explosion, ignition and generation of toxic gas during storage, transportation or handling. Caution must be taken.
Therefore, measures for minimizing these dangers are essential, and diffusion measures for uniformly generating chlorine dioxide in the earth are also essential.

In order to solve this problem, the present applicant has filed a patent application filed on September 22, 1998 (Japanese Patent Application No. 10-26
No. 8003), a powdery or granular disinfectant composition is prepared by diluting a solid component of an alkali metal salt and / or an alkaline earth metal salt of chlorite with a predetermined solid component. The present invention proposes a soil application fungicide composition capable of surely suppressing seed germination, disinfecting, and killing insects by uniformly mixing the intended soil with the means, and a soil disinfecting method using the same. This soil-applied fungicide dilutes high concentrations of dangerous chlorite with other solid components,
At the same time, safety can be dramatically improved, and at the same time, the ability to diffuse into soil can be ensured at an appropriate application rate.

However, as a result of further studies by the present inventors, it has been found that there is room for the following improvement in this fungicide for soil application. That is, along with measures to ensure that chemical changes such as decomposition due to changes in temperature and humidity during production storage are not caused, workers are required to perform 0.1 ppm, which is the prescribed allowable working concentration for chlorine dioxide during soil application preparation and application.
It has been found that it is desirable to take measures to prevent (TLV-TWA) from exceeding TLV-TWA even after application until the time of agricultural work.

The present invention has been made in view of the above-mentioned problems of the prior art and the above-mentioned problems. It is an object of the present invention to provide a method for manufacturing, storing, and applying to soil.
It is another object of the present invention to provide a time-disintegrable soil application fungicide composition having extremely enhanced safety from application to the start of agricultural work.

[0007]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, time-disintegrated a mixture obtained by diluting dangerous chlorite having a high concentration with other solid components. It has been found that the above problems can be solved by coating with a hydrophilic coating agent, and the present invention has been completed.

That is, the time-disintegrable fungicide composition for soil application according to the present invention comprises a solid sterilizing component comprising an alkali metal salt and / or an alkaline earth metal salt of chlorite, and a non-hygroscopic and reducing compound. A solid diluent containing neutral and alkaline minerals containing no inorganic salts and / or metals having a content of 0.001% by weight or less and a heavy metal oxide content of 0.1% by weight or less. It is characterized by being coated with a disintegrating coating agent.

A preferred form of the time-disintegrating soil-applied fungicide composition of the present invention is a bifunctional or trifunctional silane coupling agent and a trifunctional or tetrafunctional alkoxysilane, which are optionally combined. It is characterized by containing a silicone oligomer or silicone polymer obtained by hydrolysis.

[0010] Further, another preferred embodiment of the time-disintegrating soil-applied fungicide composition of the present invention is a non-hygroscopic inorganic salt containing no reducing compound, which is selected from the group consisting of sulfuric acid, nitric acid, hydrochloric acid and carbonic acid. At least one alkali metal salt and / or alkaline earth metal salt of at least one selected acid, wherein the neutral to alkaline minerals are at least one selected from the group consisting of silica sand, talc, perlite and bentonite. It is of a kind.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. As described above, this time-disintegrating soil-applied fungicide composition comprises a time-disintegrating coating agent comprising a solid disinfectant comprising an alkali metal salt of chlorite and / or an alkaline earth metal salt and a predetermined solid diluent. It is covered with.

Here, the alkali metal salt and alkaline earth metal salt of chlorite typically include sodium chlorite, potassium chlorite or calcium chlorite, and any mixture thereof. Sodium chlorite is widely used industrially, and sodium chlorite is preferred from the viewpoint of easy availability. In addition, the solution of sodium chlorite is distributed at 25% to 40%, but as a solid of sodium chlorite to be used in the present invention,
50% to 80% are in circulation. Chlorite concentrations above 80% are meaningless as they are highly explosive and virtually impossible to handle.

Further, the solid diluent is a non-hygroscopic inorganic salt containing no reducing compound or a metal content of 0.025% or less.
Purified and dried neutral to alkaline, preferably neutral mineral products having a content of heavy metal oxides of 0.1% by weight or less and 0.1% by weight or less, and mixtures thereof. It is important to select inorganic salts that do not contain a redox substance as an impurity and have no hygroscopicity. Similarly, neutral to alkaline mineral products have a heavy metal oxide content of 0.1% by weight or less, preferably 0.01% by weight.
It must be well-dried, not more than weight percent. If these conditions are not satisfied, chlorine dioxide gas may be generated from the solid during storage, which is dangerous.

As a specific example of the above reducing compound,
Are sulfur compounds, thiosulfates, sulfites, sugar, etc.
And heavy metal oxides include iron rust (F
e₂O ₃), Manganese dioxide and chromium trioxide
I can do it. Also, what has been sufficiently dried
Typically, it means a water content of 0.1 to 1% by weight.

In a preferred embodiment of the present invention, the non-hygroscopic inorganic salts containing no reducing substance include sulfuric acid, nitric acid, hydrochloric acid or carbonic acid, and alkali metal salts or alkaline earth metal salts of mixed acids thereof. And these are 1
Species can be used alone or as a mixture of two or more. Specifically, sodium sulfate, potassium sulfate,
Examples include calcium sulfate, magnesium sulfate, potassium nitrate, sodium nitrate, calcium nitrate, magnesium nitrate, sodium chloride, potassium chloride, calcium carbonate or magnesium carbonate, and any mixture thereof.

On the other hand, specific examples of the neutral to alkaline minerals include silica sand, talc, pearlite, bentonite and the like, and these may be used alone or in any combination of two or more. be able to. Needless to say, the above inorganic salts and neutral to alkaline mineral products can be used in combination.

Further, the above-mentioned coating agent is obtained by co-hydrolyzing a silane coupling agent having a bifunctional or trifunctional alkoxy group and an alkoxysilane having a trifunctional or tetrafunctional alkoxy group in any combination. It preferably contains a silicone oligomer or silicone polymer. Examples of such a silicone oligomer or silicone polymer include JP-A-7-224169, JP-A-7-138369, JP-A-7-138371, and JP-A-7-138371.
145241, JP-A-7-149903, JP-A-7-
157562 and the substances described in JP-A-7-165921 are particularly preferred.

Further, an example is shown below. Such a silicone oligomer is represented by the general formula [1] Si (OR ₁ ) ₄ ... [1] (wherein R ₁ is a C ₁ -C ₈ alkoxy group) And a tetraalkoxysilane represented by the general formula [2]:

[0019]

Embedded image

(Wherein R represents a C ₁ -C ₈ saturated hydrocarbon group or alkenyl group, and R ₂ represents a C ₁ -C ₈ alkoxy group) 3-glycidoxypropyl dialkoxysilane And in the presence of a catalytic amount of an organotin condensation catalyst, in a hydrophilic solvent or a mixed solvent containing a hydrophilic solvent, co-hydrolyze by adding 3 to 4 moles of water to the total moles of silane to condense. Is obtained by

The substituent R of the alkoxysilane in the general formula [2] is preferably a C ₁ -C ₈ saturated hydrocarbon group or an alkenyl group, and particularly preferably a C ₁ -C ₂ saturated hydrocarbon group or a vinyl group. Is preferred. When the C ₆ smaller substituents, since the coating agent through the water to some extent, because the moisture in the soil to penetrate the coating, dissolving the coating agent and soil application fungicides. Also, an alkoxy group R ₁ and R ₂ alkoxysilane above general formula [1] and in the general formula [2] are those derived from saturated alcohols of C ₁ -C _8, C ₁ considering the reaction rate it is preferred ones -C _3.

Another example is obtained by reacting tetraalkoxysilane and 3-glycidoxypropylmethyldialkoxysilane at a molar ratio of 1: 1. The following general formula [3]

[0023]

Embedded image

(X in the formula is 0.5 to 1.5, and R is as described above). The silicone polymer is in an oil state at normal temperature. In addition, infrared absorption (IR) 3450 cm
Absorption peak near ^-1 (from Si-OH) and 2940c
Absorbance (l) with an absorption peak (derived from CH) near m- ¹
(logI0 / I) ratio is 1.0 or less, and the terminal group of this silicone polymer is a silanol group. Further, the silicone polymer can be easily isolated by ordinary separation operations,
It is a stable organopolysiloxane oil that is soluble in various organic solvents.

The coating agent is preferably used by adding a thermosetting resin having compatibility with the silicone oligomer or silicone polymer and a curing agent thereof. A specific example of such a thermosetting resin is an epoxy resin. In the present invention, it is preferable that the above-mentioned silicone oligomer or polymer is blended with an epoxy resin, and the blended resin is cured by adding an epoxy curing agent.

The disintegration time of the time-disintegrating fungicide composition for soil application according to the present invention in soil is preferably adjusted to 12 to 72 hours. The disintegration time is controlled by the thickness of the coating agent. Assuming that the average film thickness of the coating agent is 100 μm based on the soil having a standard porosity based on the field soil moisture of 60%, the time-disintegration time of the soil application fungicide composition is 18 hours. Such timed disintegration time can be arbitrarily set from 12 hours to 120 hours.

The time-disintegrating fungicide composition for soil application according to the present invention comprises the above-mentioned chlorite as a solid fungicide, an inorganic salt and / or a neutral to alkaline mineral product as a solid diluent, Contains a coating agent, the content of each component, as long as the present invention exhibits the intended bactericidal and safety,
Although not particularly limited, typically, the coating agent is contained in an amount of 0.01 to 10 parts by weight with respect to 100 parts by weight of the mixture of the solid germicide and the solid diluent. 0.1 to 85% by weight of a solid sterilizing component and 99.9 to
It preferably comprises 15% by weight of the solid diluent component.
When the amount of the coating agent is less than 0.01 part by weight, mechanical strength is insufficient, and when it exceeds 10 parts by weight, it is difficult to obtain disintegration, which is not preferable. Further, when the amount of chlorite is less than 0.1% by weight, a large amount is required to secure a predetermined soil application rate, which is not practical. On the other hand, if it exceeds 85%, explosive properties may be exhibited due to impact or heat during handling, which is not preferable.

The properties of the time-disintegrable soil-applied fungicide composition of the present invention are solid as described above. Specifically, a mixed powder of the above-mentioned fungicide component, diluent component and coating agent is used. It is a substance or a granular substance. As its shape,
A spherical shape is preferable, but a cylindrical shape or another shape may be used. Further, it is preferable that both components are uniformly mixed.

The time-disintegrable soil application fungicide composition of the present invention is typically applied by spraying the soil, tilling the soil, and uniformly mixing the soil. As a result, the coating agent and the fungicide composition for soil application are disintegrated by the moisture in the soil, and chlorine dioxide gas is generated in the soil. At this time, the depth of tillage can be appropriately changed according to the intended herbicidal properties, insecticidal properties, bactericidal properties, virucidal properties, and the like. Typically, 15 to 20 cm is sufficient, Deep cultivation of 30 to 60 cm may be performed once every several times. Such deep cultivation is extremely effective depending on the type of disease in the target soil.

The application rate is 0.01 to 1 solid fungicide component per 1 kg of soil.
It is preferably set to 00 g. That is, 85% by weight or less of chlorite diluted with the solid diluent is added to 1 kg of soil.
It is preferable to apply 0.01 g to 100 g as a chlorous acid component. 10m chlorite component in soil
When the amount is less than g / kg (10 ppm), the function as a bactericide composition may not be sufficiently performed, and may be less than 100 g / kg.
If it exceeds (10%), chlorite remains in the soil, which may hinder planting, which is not preferable. In addition,
If the target soil is high in organic matter such as nursery soil or culture soil, the absorption of chlorine dioxide is about 20 to 30% higher than that of ordinary soil. Good results are obtained by increasing the amount of salt.

[0031]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[Adjustment of Coating Agent] A silanol group-containing polysiloxane-3-glycidoxypropylmethylpolysiloxane copolymer oil was synthesized as a silicone polymer. 70 g of ethyl orthosilicate (manufactured by Tama Chemical Co., Ltd.) is placed in a 1 L three-necked flask, and 500 ml of a mixed solvent of toluene / methanol = 60/40 is added as a reaction solvent.
Hydrochloric acid as a hydrolysis catalyst and 64 ml of water 3.5 times the molar amount of the catalyst were added, and the mixture was reacted at room temperature and under stirring for 30 minutes. Thereafter, gas chromatography (GC) confirmed that the peak of ethyl orthosilicate had disappeared. next,
To the reaction product, 148 g of 3-glycidoxypropylmethyldimethoxylane (S520 manufactured by Chisso) and 0.05 g of dibutyltin dilaurate as a condensation catalyst were added, and the mixture was subjected to a hydrolytic condensation reaction at room temperature and under stirring for 3 to 5 hours. Was. Thereafter, it was confirmed by GC that the peaks of 3-glycidoxypropylmethyldimethoxysilane and this oligomer had disappeared, and the reaction was terminated. Further, the reaction product was heated in a water bath, and methanol and an azeotropic solvent were distilled off under strong stirring. The residual liquid was transferred to a 300 ml flask, heated in an oil bath, and water containing residual toluene and hydrochloric acid was distilled off under strong stirring.

The obtained oil had a theoretical yield of 119 g.
98%, 8.7% oxirane oxygen content, C46.
3% and H 8.15%. This result is obtained by the empirical formula C
₁₄H ₂₉O₅Si₃Oxirane is a calculated value for
8.9% oxygen, 46.5% C, 8.1% H, O22.1
% And 24.1% of Si. No oil
A viscous liquid that is transparent and has a slightly sweet scent.
Has a viscosity of 7,800 centipoise (25 ° C).
Was. Confirm structure by IR chart and NMR chart
did. Also, the oil can be dissolved or
When judging the sweetness, toluene, hexane and aceto
It is readily soluble in methanol, ethyl acetate,
Dissolve in chilled ketone and chloroform and finely dissolve in ethanol.
Soluble (slightly cloudy), slightly soluble in isopropanol (cloudy), soluble in water
It was insoluble.

Next, epoxy resin 5 was added to 100 parts of the oil.
0 parts (Araldite GY260 manufactured by Chise Nagase) and 20 parts of an amine curing agent (Gascumin 328 manufactured by Mitsubishi Gas Chemical Company) were mixed and stirred, and the mixture was dissolved in n-hexane to prepare a coating agent. As a mixture of a solid disinfectant and a solid diluent, talc (manufactured by Kanto Chemical Co., Inc., loss on ignition = 5.0% max., 5%) was added to 80% by weight of sodium chlorite powder (Silbrite 80 manufactured by Nippon Carlit). A powder diluted to 2% by adding pH = 9.3) was used. As the coating agent, a silicone polymer synthesized as described above to which an epoxy resin and a diamine curing agent were added was used to obtain a time-disintegrable soil application fungicide of the present invention. That is, the coating on the potassium sulfate-diluted sodium chlorite powder was performed by repeating the operation of spraying the above-mentioned coating agent and stirring. By further reducing the pressure, the n-hexane solvent was removed to obtain a time-disintegrable soil-applied fungicide composition having various coating thicknesses.

[Evaluation of Performance] The average film thickness of the coating agent was determined by dissolving the time-disintegrable soil-applied fungicide composition in hot water at 40 ° C., leaving the shell weight of the remaining coating agent and the surface area of the soil-applied fungicide composition. Calculated from The time collapse time is
A time-disintegrating soil application fungicide composition coated on a soil application fungicide composition containing the equivalent of 600 mg of sodium chlorite is thoroughly mixed with 10 g of soil having a water content of 60% and a porosity of 50%, and placed in a 20 L desiccator. At room temperature until the chlorine dioxide gas concentration reached 10 ml / m ³ .
Table 1 shows the obtained results.

[0036]

[Table 1]

[0037]

As described above, according to the present invention,
Since the mixture containing highly concentrated dangerous chlorite diluted with other solid components is coated with a time-disintegrable coating agent, production, storage, and application to the soil are completed, and therefore, agricultural work after application Extremely high safety until the start,
A time-disintegrable soil applied fungicide composition can be provided.

Claims (6)

[Claims] 1. A solid germicide comprising an alkali metal salt and / or an alkaline earth metal salt of chlorite, and a non-hygroscopic inorganic salt containing no reducing compound and / or a metal content of 0.001% by weight. % And a solid diluent containing a neutral to alkaline mineral product having a heavy metal oxide content of 0.1% by weight or less and a time-disintegrable coating agent. Time disintegrating soil applied fungicide composition. 2. A silicone oligomer or silicone polymer obtained by co-hydrolyzing a bifunctional or trifunctional silane coupling agent and a trifunctional or tetrafunctional alkoxysilane in any combination as the coating agent. The time-disintegrable soil-applied fungicide composition according to claim 1, which is contained. 3. The time-degradable soil application according to claim 2, wherein the coating agent further contains a thermosetting resin having compatibility with the silicone oligomer or silicone polymer and a curing agent thereof. Fungicide composition. 4. The non-hygroscopic inorganic salt free of a reducing compound, wherein the inorganic salt is at least one alkali metal salt and / or alkaline earth metal selected from the group consisting of sulfuric acid, nitric acid, hydrochloric acid and carbonic acid. The salt according to any one of claims 1 to 3, wherein the neutral to alkaline mineral products are at least one selected from the group consisting of silica sand, talc, perlite, and bentonite. 3. A time-disintegrable soil applied fungicide composition according to any one of the preceding items. 5. A disintegration time in soil of from 12 to 120.
The time-disintegrable soil application fungicide composition according to any one of claims 1 to 4, wherein the composition is adjusted to time. 6. The coating agent is added in an amount of 0.01 to 100 parts by weight of a mixture of the solid germicide and the solid diluent.
6. The composition of claim 1, wherein the mixture comprises 0.1 to 85% by weight of the solid germicidal component and 99.9 to 15% by weight of the solid component.
3. A time-disintegrable soil applied fungicide composition according to any one of the preceding items.