RU2717301C1 - Fungicidal pyrotechnic composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: fungicidal pyrotechnic composition contains a smoke-forming organic fuel, a flame arrester, an oxidising agent and an active fungicidal substance pre-deposited on a porous carrier, wherein the porous support is selected from: diatomite, trefoil, pearlite, kaolin clay, vermiculite, zeolite and/or any mixture thereof, and the porous support is pre-treated with sodium, potassium or calcium alkali in weight ratio of the porous support: alkali of 1:0.01–0.7. To obtain the composition, the active substance is pre-dissolved in a suitable solvent and further mixed in a carrier suspension and a solution of the active substance, followed by removal of the solvent while heating and subsequent mechanical mixing of all components, the porous carrier being selected from: diatomite, trefoil, pearlite, kaolin clay, vermiculite, silica gel, zeolite and/or any mixture thereof, and the porous support is pre-treated with sodium, potassium or calcium alkali in the form of an aqueous suspension with a weight ratio of porous support: alkali of 1:0.01–0.7, while continuously stirring at temperature of 60–100 °C for 2–4 hours with subsequent washing carrier with hot water, grinding and drying.

EFFECT: invention increases efficiency of using the composition.

2 cl, 2 tbl, 3 ex

Description

 The invention relates to biocides, in particular to pyrotechnic compositions, which generate fungicidal smoke when burned, which are used to combat mold, inhibit the activity of microorganisms, in particular, fungal diseases of potatoes, carrots, beets, grapes and other agricultural crops.

 Known pyrotechnic smoke-generating insecticidal composition, generating an aerosol during combustion, in which the active substance described in / 1 / is dispersed, which contains, wt.%: 27-49 ammonium nitrate (oxidizing agent), 30-47 peat (organic fuel), 1 -15 permethrin is an active substance, the rest is water.

 The disadvantage of this composition is poor flammability, which requires the use of special fuses and requires qualification of the operator, additional protective measures that complicate the technology of pesticidal treatment of enclosed spaces. In addition, the composition is characterized by physical and chemical instability during storage due to the high hygroscopicity of ammonium nitrate, which is prone to polymorphic transformations, which reduces the functional reliability of the material and tablets from it.

 The functional drawback of the composition is the low efficiency of using permethrin in the treated volume for its intended purpose, which is not completely sublimated when burning pyrotechnic tablets from the described smoke-forming composition.

 Known pyrotechnic smoke-generating composition, generating during combustion an active substance (pesticide) dispersed in the structure of an aerosol, which is described in the patent / 2 /. The composition includes permethrin as an active substance, potassium chlorate as an oxidizing agent, carbamide and thiuram as an organic fuel, a binder containing chlorinated polyvinyl chloride resin, plasticized with dibutyl phthalate or tricresyl phosphate, and a technological additive containing aerosil, which are contained in the following ratio (wt.%);

Permethrin 4-12 potassium chlorate 24-36 Urea 22-38 Tiuram 6-18 chlorinated polyvinyl chloride resin 6-12 plasticizer 2-8 Aerosil 4-8.

Thiuram (GOST 740-76) is distributed as an active fungicidal agent for seed dressing and for rodent control.

 Thiuram mixed with potassium chlorate serves as a highly active fuel, which is due to its high sulfur content, which contributes to a decrease in the ignition temperature of the composition and an increase in sensitivity to optical radiation.

 The composition of potassium chlorate and urea is a traditional thermal basis for pyrotechnic compositions.

 The use of a chlorinated polyvinyl chloride resin plasticized with dibutyl phthalate or tricresyl phosphate gives the known composition plastic properties, which makes it possible to form tablets from it using progressive compression molding technology.

 The functionality of using plasticized resin is to prevent flame burning of the composition, since HC1, which is a flame retardant, is released during its thermal decomposition, which prevents the combustion of a significant amount of the active substance.

 In addition, thiuram in this thermoplastic composition acts as a hardener of plasticized resin, improving technological properties in the preparation and processing.

 Aerosil serves as a light filler for the liquid component - permethrin, preventing its exudation during compression of the composition and during storage of tablets.

 Having high adsorption properties, Aerosil stabilizes the mixture and reduces its hygroscopicity.

 A disadvantage of the known pyrotechnic smoke-forming pesticidal composition, in which the content of the active substance is limited, is its low efficiency in the fight against microorganisms.

 Known smoke-forming pyrotechnic fungicidal composition / 3 /, containing an active substance - trilane, an oxidizing agent - potassium chlorate, organic fuel - urea and gas-forming tiuram, a polymer binder - chloroparaffin XP-470 and aerosil with the following content of components, wt.%:

trilane 45-50 potassium chlorate  22-25 urea 15-20 tiuram 5-10 chloroparaffin HP-470 2-3 aerosil 1-2.

 The disadvantages of the known composition are the high content of the active substance, the low effectiveness of the drug - tests have shown that for effective processing of potatoes against these diseases, 8 g of composition per 1 m3 of volume is necessary, and when processing potato storages before filling it with potatoes, 5 g / m3 is enough. In addition, a significant price is the high price of the active substance.

Known fungicidal pyrotechnic composition, including 2- (4-thiazolyl) -benzimidazole (trade names - thiabendazole, arbotect), an oxidizing agent and fuel in the following ratio of components, mass.

Thiabendazole (TBA)  25-40 Fuel  21-26.5 Oxidizing agent  26-40 Flame arrester  1-10

 Iditol, urotropin, bakelite, dicyandiamide, a mixture of urea and thiourea in a ratio of 1: 2.5, anthracene or its mixture with dicyandiamide are used as fuel; as an oxidizing agent - chlorate and potassium nitrate. The composition contains a flame arrester in an amount of 1-10%, and ammonium chloride is used as a flame arrester / 4 /.

Массу сублимированного ТБА определяют, улавливая выделяющийся сублимат, с последующим количественным анализом сублимированного тиабендазола методом жидкостной хроматографии высокого давления. КИ приведенной выше пиротехнической композиции равен 44,1% масс. (см. таблицу 1).A characteristic of the effectiveness of the process of thermal sublimation (sublimation) TBA is the utilization factor, KI, which is calculated by the formula:

The mass of freeze-dried TBA is determined by trapping the released sublimate, followed by quantitative analysis of freeze-dried thiabendazole by high pressure liquid chromatography. CI of the above pyrotechnic composition is equal to 44.1% of the mass. (see table 1).

 The indicated technical solution provides an example of a specific pyrotechnic composition: 35 g (35% wt.) (2- (4-thiazolyl) benzimidazole (TBA), 26 g (26% wt.) Potassium chlorate, 29 g (29% wt. ) dicyandiamide and 10 g (10 wt.%) ammonium chloride, pre-dried to a moisture content of not more than 0.3 wt.% and crushed so that the particle size does not exceed 0.4 mm, are mixed and pressed either in the form of tablets or in the form of checkers, the mass and configuration of which is determined by the mold, as well as the volumes and specifics of the processed objects and can be within 0.5 -500 g. Tablets and checkers are put into action, setting fire to the surface with a match, a hole.

 A disadvantage of the known technical solution is the low degree of sublimation of the active substance - thiabendazole. This is proved by the data of the table in the known technical solution, where the utilization of the active component does not exceed 55%. In reality, this coefficient is even lower, which means that in fact more than half of the active substance of the composition simply burns out, being in fact one of the components of the organic fuel of a pyrotechnic product. One of the reasons for this phenomenon is that mixtures of this composition have a too high combustion (smoldering) temperature, which exceeds 500 ° C according to measurements.

 The closest in its technical essence and the achieved result is an insecticidal block described in / 5, a prototype / and containing a pyrotechnic composition, in which the active substance is dispersed in the mass of the organic smoke forming part of the pyrotechnic composition, which ensures the absence of direct contact with a burning oxidizing agent, protecting active substance from partial thermal decomposition.

In an embodiment, the checker contains a pyrotechnic composition and microcapsules, and / or porous particles, and / or hygroscopic granules with an active substance distributed in a pyro-composition or located separately from the pyrotechnic composition by means of a separation membrane with at least one opening.

In another embodiment, the checker comprises a gas filter element made of a porous and / or hygroscopic material and impregnated with the active substance. The element can be made with reefs, contributing to the outflow of gaseous products.

 -циперметрин, или хлорпирифос, или эток (2,2-диметил-3-(2-метил-1-пропенил)циклопропанкарбоновой кислоты 2-метил-4-оксо-3-(2-пропинил)циклопентен-1-иловый эфир) или другие соединения, отвечающие требованию безопасности и обладающие свойствами, необходимыми для применения их в предложенных конструкциях шашки.As an active substance - an insectoacaricidal component, compounds of the pyrethroid group can be used: permethrin, cypermethrin or

-cypermethrin, or chlorpyrifos, or this (2,2-dimethyl-3- (2-methyl-1-propenyl) cyclopropanecarboxylic acid 2-methyl-4-oxo-3- (2-propynyl) cyclopenten-1-yl ester) or other compounds that meet the safety requirement and possess the properties necessary for their use in the proposed constructions of the checker.

As a pyrotechnic smoke-forming composition, a composition may be used including: potassium chlorate, ammonium chloride, organic smoke-forming agent (hydrocarbon fuel): wax, rosin, or paraffin, etc. and chalk. As a result of this, the organic smoke generator forms a continuous medium (matrix) in which the remaining components are distributed. In this case, the insecticide is dispersed / emulsified within the mass of the smoke generator. This location of the insecticide isolates it from the direct effects of high temperatures during the combustion of the oxidizing agent, and therefore, from partial thermal decomposition. The resulting matrix contributes to uniform heating of the entire mass of the composition. The pyrotechnic mixture obtained in this way has the character of uniform layer-by-layer combustion (decay), calm without flashes.

Option checkers involves microencapsulation of the active substance or impregnation of porous particles (granules). Microcapsules with the active substance are obtained according to the known microencapsulation technology, and porous particles and granules are pre-impregnated with the active substance. In the distribution of microcapsules or impregnated particles in the pyrocomposition, in both cases, isolation of the active substance from direct decomposing factors is also achieved. As porous particles, for example, silica gel or coal can be used. The distribution of the active substance in the mass of the pyrotechnic organic smoke generator is achieved by mixing the solution of the active substance and the smoke generator solution in appropriate solvents (in the case of the above components, the solvent may be acetone or alcohol), then mixing the resulting solution with the other components of the composition and heating the resulting mass until the solvent is completely removed . The examples of the substances used are preferred, but do not limit the possibilities.

 A disadvantage of the known technical solution is the connection of the molecules of the active substances due to the Van der Waals adhesion forces with the developed surface of the porous carrier, which leads to delays in the sublimation of active substances and local overheating. This fact does not allow to increase the efficiency of using this type of checkers (no more than 60% of the active substances pass into aerosol, the rest decompose or burn out).

The objective of this technical solution is to further increase the utilization of the active substance by increasing the completeness of the sublimation of active substances in fungicidal pyrotechnic pieces.

The second objective of this technical solution is to create a method for producing fungicidal pyrotechnic checkers, allowing to produce checkers with a high coefficient of useful use of the active preparations that make up the checkers due to more efficient sublimation of active substances during checker smoldering.

The first problem is solved by the claimed fungicidal pyrotechnic composition containing a smoke-forming organic fuel, a flame arrester, an oxidizing agent and an active fungicidal substance previously applied to a porous carrier, characterized in that the porous carrier is selected from the group: diatomite, tripoli, perlite, kaolin clay, vermiculite, zeolite and \ or any mixtures thereof, and the porous carrier is pretreated with sodium, potassium or calcium alkali in a weight ratio of porous carrier: alkali of 1: 0.01 - 0.7.

The second problem is solved by the claimed method of obtaining a fungicidal pyrotechnic composition containing a smoke-forming organic fuel, a flame arrester, an oxidizing agent and an active fungicidal substance, previously deposited on a porous carrier by preliminary dissolution in a suitable solvent and further mixing in a suspension of the carrier and the solution of the active substance, followed by removal of the solvent by heating and further mechanical mixing of all components, characterized in that the porous carrier you wounds from the group: diatomite, tripoli, perlite, kaolin clay, vermiculite, silica gel, zeolite and / or any mixtures thereof, and the porous carrier is pretreated with sodium, potassium or calcium alkali in the form of an aqueous suspension at a weight ratio of porous carrier: alkali of 1 : 0.01 - 0.7 with constant stirring at a temperature of 60-100 ° C for 2-4 hours, followed by washing the filler with hot water, grinding and drying.

 -циперметрин, тиурам, септабик, катамин АБ, метил-третбутиламмоний бромид, дифеноконазол, ципроконазол, кабоксин и тачигарен, а также любые их смеси.Examples of active components that can be used in the proposed technical solution, but without limiting its capabilities, are thiabendazole, permethrin, cypermethrin,

-cypermethrin, thiuram, septabic, catamine AB, methyl tert-butyl ammonium bromide, diphenoconazole, ciproconazole, caboxin and tachigaren, as well as any mixtures thereof.

 The claimed technical solution is illustrated by the following examples:

 Example 1 of the prototype (comparative).

 The pyrotechnic product is prepared according to the method described in the prototype, previously impregnating silica gel with a solution of permethrin in acetone. To do this, dissolve 25 grams of permitrin in acetone and mix the resulting solution with 50 grams of silica gel pre-crushed to a powder state in the form of a suspension, after which the resulting mass is transferred to a rotary evaporator flask and acetone is removed with continuous stirring under a residual vacuum of 25 mm Hg. and heating at a temperature of 45 ° C to the state of the powder, when the solvent (acetone) ceases to distill off, and the filler with the sorbed active additive easily moves along the bottom of the flask during rotation of the flask of a rotary evaporator. A total of 74.7 g of permitrin mixed with silica gel are obtained.

 The obtained powder of silica gel coated with permitrin in an amount of 60 g is mixed with 30 g of potassium chlorate (oxidizing agent), 35 g of urotropin (organic fuel-smoke former) and 10 g of ammonium chloride (flame arrester), previously dried to a moisture content of not more than 0.3% wt. . and crushed so that the particle size does not exceed 0.5 mm. The active substance content in the resulting composition is (25 x 60 x 100%) / ((74.7 x (60 + 30 + 35 + 10)) = 14.8%. This pyrotechnic composition is placed in a plastic cup, sealed and filled with a fuse - a hunting match. Then the finished checker is transferred to a hermetically sealed room with an internal volume of 225 m3, equipped with a powerful domestic fan to evenly distribute a cloud of smoke throughout the room. The fan is turned on, the checkers are ignited and quickly leave the room. The checker burns quietly and is released when burning d It forms a continuous aerosol cloud with the same concentration of the active substance, permethrin, and then a smoke sample is taken through a valve and analyzed by HPLC for the content of permethrin in a smoke aerosol cloud.

 The effectiveness of the composition was determined according to the principle set forth in / 4 / by determining the fraction of the active substance, which passed due to sublimation into an aerosol state.

 Using simple calculations, it is found out from the analysis that up to 62 masses of permethrin were released into the atmosphere of the chamber. % of the active substance originally contained in the checker.

 Example 2 (according to the claimed technical solution).

 The pyrotechnic composition and the block are made as described in example 1, but thiabendazole is used as the active substance, and finely divided diatomite is used as the filler, which is pretreated with calcium alkali according to the following procedure: 100 grams of diatomite powder is placed in a round bottom flask with a turbine stirrer and filled 250 grams of an aqueous 20% suspension of calcium lime (hydrated lime). The mass ratio of the porous carrier: alkali is 1: 0.5. The stirrer is turned on and the temperature in the flask is brought to 80 ° C, after which they continue to vigorously mix the contents of the flask for 3 hours. Then the flask is cooled and the precipitate is filtered off, repeatedly washed with hot water until the filtrate is neutral, after which it is dried in a vacuum oven at 60 ° C.

 Then, the alkali-modified carrier obtained is ground and used in the manufacture of a pyrotechnic composition. To do this, dissolve 35 grams of thiabendazole in chloroform and mix the resulting solution with 60 grams of alkali-pretreated diatomaceous earth powder in suspension, then transfer the resulting mass to a flask of a rotary evaporator and remove chloroform with continuous stirring under a residual vacuum of 25 mm Hg. and heating at a temperature of 45 ° C to the state of the powder, when the solvent (chloroform) ceases to distill off, and the filler with the sorbed active additive easily moves along the bottom of the flask during rotation of the flask of a rotary evaporator.

 The described methods of processing the carrier with alkali using a turbine mixer and applying the active additive on the porous filler using a rotary evaporator does not limit the method in any way and can be replaced by any other methods known to the expert, for example, using solvent distillation under vacuum using ultrasound to uniformly mix the components , or any other well-known tricks.

 The obtained powder of modified diatomite coated with thiabendazole in an amount of 60 g is mixed with 30 g of potassium chlorate (oxidizing agent), 35 g of urotropin (organic fuel-smoke generator) and 10 g of ammonium chloride (flame arrester), previously dried to a moisture content of not more than 0.3% wt. and crushed so that the particle size does not exceed 0.5 mm. The active substance content in the resulting composition is (35 x 60 x 100%) / ((60 + 35) (60 + 30 + 35 + 10) = 16.7%. The resulting pyrotechnic composition is placed in a plastic cup, compacted and supplied with a fuse - Then, the finished checker is transferred to a hermetically sealed room with an internal volume of 225 m3, equipped with a powerful domestic fan to evenly distribute a cloud of smoke throughout the room. The fan is turned on, the igniters of the checkers are ignited and quickly leave the room. the smoke forms a continuous aerosol cloud with the same concentration of the active substance thiabendazole. Then the smoke sample is taken through the valve and analyzed by HPLC for the content of thiabendazole in the aerosol smoke cloud. It is determined by analysis that thiabendazole was released into the chamber atmosphere up to 83 wt%. from the active substance originally contained in the checker.

 Example 3

 A mixture of tripoli and zeolite A 1: 1 is used as a porous carrier, permitrin is used as an active substance, which was dissolved in acetone during application, sodium hydroxide was used as alkali, and the filler was processed at 100 ° С for 2 hours. In the manufacture of checkers, dicyandiamide was used as fuel, and a mixture of ammonium chloride and finely divided chalk 1: 1 was used as a flame arrester. All other parameters coincided with example 2. The content of active substance in the checker was 16.9%. As a result of burning the resulting checkers, 76% of the initial amount of permitrin passed into the aerosol smoke cloud.

 Example 4

 All conditions coincide with example 3, but as the active substance using a mixture of thiabendazole with permitrin 1: 1. As a result of the use of checkers, 73% of permitrin and 80% of thiabendazole are transferred to the aerosol cloud.

 The conditions for obtaining fungicidal pyrotechnic compositions and the results of their use in examples 1-17 are presented in Table 2.

 Table 2.

Conditions for obtaining fungicidal pyrotechnic compositions and their effectiveness.

Example No.
Active substance Porous aggregate and ratio fill.: Alkali The type of alkali and the content of active substance in the composition, wt.% Temperature (° C) and processing time. fill in. (hour) Fuel and flame arrester % of the mass. active substance in an aerosol cloud of the initial amount 1 (prototype). Permitrin Silica gel, - -, 14.8 - Urotropin and ammonium chloride 62 2. Thiabendazole Diatomite, 1: 0.5 Hydrated lime, 16.7 80, 3 Urotropin and ammonium chloride 83 3. Permitrin Tripoli and zeolite NaA, 1: 1, 1: 0.5 NaOH, 16.7 100, 2 Dicyandiamide and a mixture of chalk with ammonium chloride 76  4. Thiabendazole with permitrin, 1: 1 Tripoli and zeolite CaA, 1: 1, 1: 0.4  NaOH, 16.6 100, 2 Dicyandiamide and a mixture of chalk with ammonium chloride 73 (for tiabenda ash) and 80 (for permitrin) 5. Tiuram and Septabik, 1: 2 Perlite, 1: 0.05 KOH, 17.4 60, 2  Anthracene and a mixture of chalk with ammonium chloride 75 each 6. Thiabendazole and diphenoconazole 2: 1 Vermiculite + Zeolite natural "natrolite", 1: 1, 1: 0,01  KOH, 22.8 60,
4 Rosin and Ammonium Chloride 76 and 70, respectively 7. Thiuram and Cyproconazole 1: 3 Silica gel, 1: 0.5 Hydrated Lime, 31.5 90, 3,5 Iditol and ammonium chloride 71 and 78, respectively 8.  thiabendazole, permethrin and caboxin, 1: 1: 1 Diatomite and vermiculite, 1: 1, 1: 0.5 Hydrated Lime, 29.4 100, 3 Bakelite and ammonium chloride 72, 80 and 77 respectively nine.  Caboxin and tachigaren, 1: 1 Diatomite, kaolin clay and perlite, 1: 1: 1, 1: 0.5 Hydrated lime, 36.5 90, 3,5 Wax and ammonium chloride 71 and 82 respectively ten. Thiabendazole and permethrin, 1: 1 Vermiculite and silica gel, 1: 3, 1: 0.4 Hydrated Lime, 41.0 90, 3 Urotropin and ammonium chloride 91 and 82 respectively eleven. Thiabendazole and tachigaren, 1: 1 Diatomite and natural zeolite "Shabazit" 2: 1, 1: 0.5 Hydrated Lime, 42.1 90, 3,5 Urotropin and ammonium chloride 70 and 90 respectively 12. Thiabendazole Kaolin clay, 1: 0.6 Hydrated lime, 38.7 90, 3,5  Paraffin and ammonium chloride 85 thirteen. Thiabendazole and cypermethrin, 3: 1.3 Diatomite and silica gel, 1: 1, 1: 0.5 Hydrated lime, 43.0 90 3,5  Thiourea urea and ammonium chloride 92 for each component fourteen. Thiabendazole and cypermethrin, 3: 1.3 Diatomite and silica gel, 1: 1, 1: 0.5 Hydrated lime, 43.0 60,
4 Thiourea urea and ammonium chloride 91 for each component fifteen.

 -циперметрин, 3:1,3Thiabendazole and

cypermethrin 3: 1.3 Diatomite and silica gel, 1: 1, 1: 0.5 Hydrated lime, 43.0 60,
4 Thiourea urea and ammonium chloride 90 for each component 16. Catamine AB Diatomite and silica gel, 1: 1, 1: 0.5 Hydrated lime, 43.0 60,
4 Thiourea urea and ammonium chloride 88 17. Methyl Tritrebutyl Ammonium Bromide Diatomite and silica gel, 1: 1, 1: 0.5 Hydrated lime, 43.0 60,
4 Thiourea urea and ammonium chloride 85

As follows from the data of table 2, the composition allows to increase the yield of active substance in the aerosol cloud of smoke up to 92% of the active component originally contained in the composition. This allows you to make the use of the composition more effective and / or more economical.

 Sources of information taken into account:

1. PCT Application WO 88/1007, A01N 25/18, 1988

2. Patent RU 2084147C1, A01N 25/20, 1997

3. Patent RU 2487539, A01N 25/20, 2013

4. Patent RU 206476, A01N 25/20, 1996.

5. RF patent No. 2458506, A01N 25/00, 2012

Claims (2)

1. A fungicidal pyrotechnic composition containing a smoke-forming organic fuel, a flame arrester, an oxidizing agent and an active fungicidal substance preliminarily applied to a porous carrier, characterized in that the porous carrier is selected from the group: diatomite, tripoli, perlite, kaolin clay, vermiculite, zeolite and / or any mixtures thereof, and the porous carrier is pretreated with sodium, potassium, or calcium alkali in a weight ratio of porous carrier: alkali of 1: 0.01–0.7. 2. A method of obtaining a fungicidal pyrotechnic composition containing smoke-forming organic fuel, a flame arrester, an oxidizing agent and an active fungicidal substance, previously deposited on a porous carrier by preliminary dissolution in a suitable solvent and further mixing in a suspension of the carrier and the solution of the active substance, followed by removal of the solvent by heating and subsequent mechanical mixing of all components, characterized in that the porous carrier is selected from the group: diatomite, tripoli, ne lithium, kaolin clay, vermiculite, silica gel, zeolite and / or any mixtures thereof, and the porous carrier is pretreated with sodium, potassium or calcium alkali in the form of an aqueous suspension at a weight ratio of porous carrier: alkali of 1: 0.01-0.7 , with constant stirring at a temperature of 60-100 ° C for 2-4 hours, followed by washing the carrier with hot water, grinding and drying.