RU2469536C1 - Fungicidal agent and method of its production - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: fungicidal agent contains tebuconazole and water soluble natural or synthetic polymers from the group of beta-cyclodextrin, arabinogalactan, hydroxyethyl starch, pectin polyethylene glycol, polyvinylpyrrolidone, at the weight ratio of 1:(1-5), respectively. The agent is produced by means of mechanochemical interaction of the said components.

EFFECT: invention enables to increase water solubility of the fungicidal agent and to increase its fungicidal activity.

9 cl, 5 tbl, 9 ex

Description

The invention relates to agriculture, namely to the creation of fungicidal preparations, and may find application in the protection of crops from root rot and other diseases.

Tebuconazole - the technical name of the active substance / 4,4-dimethyl-3- (1H-1,2,4-triazol-1-ylmethyl) -1-n-chlorophenylpentan-3-ol / belongs to the class of organic compounds (namely class of triazoles), and by biological activity - to systemic fungicides of a wide spectrum of action for combating diseases of leaves and ears of grain (fusarium, Septoria, rust, powdery mildew and others), gray rot of grapes, some diseases of soy, rape, sunflower, vegetable and fruit crops by spraying and seed dressing for control with solid and dusty smut, septoria of cereals [Melnikov NN, Novozhilov KV, Belan S.R. Directory. Pesticides and plant growth regulators. M .: Chemistry, 1995].

Due to the poor solubility of the active substance in water (32 mg / l), the effectiveness of drugs based on tebuconazole (Tebu, Barrier-Color, Raxil, Vial-Trust, Stinger, etc.) is not so high and the consumption rates of drugs are 0.5-1 2 kg / t of seeds. Well-known methods for changing technological parameters of tebuconazole (including water solubility) are the development of various preparative forms of application [Methodological recommendations for monitoring the quality of preparative forms of CSF and feedstock for their preparation. Cherkasy, NIITEKHIM, 1984, 48 pp.].

Such forms for tebuconazole are formulations in the form of suspension concentrates (Barrier-Color, Vial-Trust, Stinger, Alt-Sil) and oil emulsions (Tebu, Scarlet) [State catalog of pesticides and agrochemicals approved for use in the Russian Federation. M., 2010, 840 pp.]. To prepare suspension forms, the substance of the preparation is dispersed in ball and bead mills in an aqueous (or aqueous-organic) medium with the addition of surfactants, stabilizers and other fillers. Oil emulsions are prepared by dissolving the substance of the drug in an organic solvent (or mixture of solvents) with the addition of a surfactant that forms a stable emulsion with water [Methodological recommendations for monitoring the quality of CSF formulations and feedstock for their preparation. Cherkasy, NIITEKHIM, 1984, 48 pp.].

As a prototype for the invention described below, the formulation of tebuconazole in the form of the drug “Raxil”, KS (60 g / l), which is recommended for the treatment of seeds of grain crops in the fight against root rot [State catalog of pesticides and agrochemicals approved for use in the territory, was selected Russian Federation. M., 2010, 840 pp.]. This formulation is obtained by wet grinding the active ingredient of the drug “Raxil” (tebuconazole) with auxiliary substances of the formulation (wetting agents, dispersants, emulsifiers, surfactants, etc.) in a liquid medium.

There is also known a method of obtaining a fungicidal agent (EP 2269581, publ. 05.01.2011) containing a fungicide in the form of nanoparticles and natural or synthetic water-soluble polymers in the ratio fungicide: polymers 1: (1-100).

However, the known method requires the presence of solvents, energy-intensive processes of spray or freeze drying, characterized by a multi-stage process.

The objective of the present invention is to increase the solubility of the fungicidal agent in water and increase its fungicidal activity.

The solution of this problem is achieved by creating a fungicidal agent containing tebuconazole and water-soluble polymers in a mass ratio (1: 1-5), respectively. As water soluble polymers, synthetic and natural polymers are used, for example polyethylene glycol, polyvinylpyrrolidone, beta-cyclodextrin, arabinogalactan, hydroxyethyl starch and pectin. The fungicidal agent is presented in the form of a water-soluble powder, while its particle sizes are in the range of up to 10 μm, and the content of nanofractions is 41-96%.

The proposed fungicidal agent have the following advantages:

- the use of affordable and cheap water-soluble polymers capable of forming mechanochemical complexes with tebuconazole;

- the water solubility of the complexes in molecular form, and not in the form of aqueous suspensions or aqueous-organic emulsions, will improve the fungicidal properties of tebuconazole;

- the use of useful technological and biological properties of the water-soluble polymers themselves, which will not only improve the quality indicators of mechanochemical complexes, but also achieve the synergistic effect in the fungicidal action of tebuconazole.

The solution to this problem is also achieved by the fact that the claimed fungicidal agent is obtained by mechanochemical interaction of tebuconazole and water-soluble polymers in a ratio of 1: (1-5). As water soluble polymers, synthetic and natural polymers are used, for example polyethylene glycol, polyvinylpyrrolidone, beta-cyclodextrin, arabinogalactan, hydroxyethyl starch and pectin.

As apparatuses for mechanochemical processing, ball roll, planetary, vibrational, vibrocentrifugal, etc. can be used. mills, i.e. shock abrasion devices. The process scales from ball laboratory mills with a load of several grams to flow vibrocentrifugal mills with a capacity of up to 100 kg / h and more.

A mixture of tebuconazole and polymers, taken in a mass ratio of 1: 1 to 1: 5, is subjected to mechanochemical treatment in the above shredders-activators of shock-abrasive type. During machining, the dispersion of tebuconazole molecules into the internal and external pores of the polymer forms a solid solution, which is a disordered solid phase in which the tebuconazole and polymer molecules experience non-covalent non-ionic interactions. During the dissolution of this solid dispersion, the release of tebuconazole occurs in the form of its complexes and therefore a high rate of water solubility is observed.

Thus, the claimed advantages of mechanochemical complexes are achieved - a high indicator of water solubility, which determines the corresponding indicator of fungicidal action. At the same time, the following declared advantages of the production method are achieved — the preparation of mechanochemical complexes takes place in one technological stage of mechanical processing in the grinder-activator, the participation of liquid phases is not required, the energy-intensive and lengthy process of drying the material is excluded, there are no waste solvents.

There are no special requirements for controlling the humidity of the premises, since the substances are processed in the sealed internal volume of the mills. In all cases, the process is carried out in virtually one stage, it does not require expensive equipment and is easy to implement.

For a better understanding of the invention, the following examples are given.

Example 1. Obtaining fungicidal agents based on tebuconazole and arabinogalactan.

0.6 g of tebuconazole (TBA), 3.0 g of arabinogalactan (AG) and 89 g of balls (diameter 4-5 mm) are loaded into metal drums (two twin drums of 100 ml each) of the MAC-1-2 activator grinder. Activation is carried out at an energy intensity of 40 g for 5 minutes. After activation, the product in the form of a loose powder is unloaded and characterized according to the analysis of dispersion (table 1a) and water solubility (table 1).

Example 2. Obtaining fungicidal agents based on tebuconazole and polyvinylpyrrolidone (PVP).

Analogously to example 1: from 0.6 g of TBA and 3.0 g of PVP in a MAC-1-2 mill, free-flowing powder of the mechanochemical complex of TBA and PVP is obtained.

Example 3. Obtaining fungicidal agents based on tebuconazole and polyethylene glycol (PEG).

Analogously to example 1: from 0.6 g of TBA and 3.0 g of PEG in a MAC-1-2 mill, free-flowing powder of the mechanochemical complex of TAC and PEG is obtained.

Example 4. Obtaining fungicidal agents based on tebuconazole and beta-cyclodextrin.

2.0 g of tebuconazole (TBA), 2.0 g of beta-cyclodextrin (CD) and 96 g of balls (diameter 4-5 mm) are loaded into metal drums (two twin drums of 50 ml each) of the AGO-2 grinder-activator. Activation is carried out at an energy intensity of 40 g for 5 minutes. After activation, the product in the form of a slightly hygroscopic powder is discharged and characterized according to the analysis of dispersion and water solubility.

Example 5. Obtaining fungicidal agents based on tebuconazole and hydroxyethyl starch (HES).

10.0 g of tebuconazole (TAC), 20.0 g of HES and 900 g of metal balls (diameter of balls 23-25 mm) are loaded into a 500 ml metal drum and processed in a VM-1 roller mill for 2 hours at a grinding speed of 1 g. The bulk powder obtained after activation of the complex of the TBK-HES composition (1: 2) is analyzed for water solubility and dispersion.

Example 6. Obtaining fungicidal agents based on tebuconazole and pectin.

Analogously to example 5: from 5.0 g of TBA and 15.0 g of pectin in a roller mill VM-1 receive a loose powder of the mechanochemical complex TBA-pectin (1: 5).

Example 7. Determination of the water solubility of fungicidal agents TBA with polymers.

Determination of the water solubility of the initial TBA and its mechanochemical complexes with polymers is carried out by HPLC under the following conditions:

- Agilent 1200 chromatograph;

- Zorbax Eclipse XDB-C18 column, 4.6 × 150 mm;

- column temperature 30 ° C;

- eluent - 25% acetonitrile + 75% water; flow rate - 1 μl / min;

- diode array detector, detection in the range of 230-280 nm.

According to the retention time data, the water solubility index of the analyzed products is calculated. The results are presented in table 1.

Example 8. Determination of the degree of dispersion (fineness) of fungicidal agents TBA with polymers.

The dispersion of the initial, ground TAC and its mechanochemical complexes is determined on a Shimadzu company SALD-7101 (SALD-7101 Nanoparticle Size Analyzer) laser particle size analyzer. Data processing was carried out according to the methodology of standard software Windows XP Professional. The analysis results are shown in table 1A. It can be seen from the table that the mechanochemical complexes have a significantly lower particle size, which once again confirms the inclusion of particles in the pores of the polymer. In addition, in compositions with AH and HES there is a significant formation of the so-called nanofractions, which are responsible for high fungicidal activity.

The fungicidal activity of the drug is determined by many factors (formulation, adherence, processing method, etc.). One of the main parameters determining the fungicidal activity of tebuconazole is its solubility. During the joint mechanochemical treatment of the tebuconazole substance with polymeric substances, we succeeded in changing the water solubility index (Table 1), which significantly increased the fungicidal effect of the claimed complexes.

To understand the essence of the invention, we compare the fungicidal activity of the proposed mechanochemical complexes with the drug "Raksil" (see table 2-5).

Example 9. Testing for fungicidal activity.

Laboratory experiments were carried out on the seeds of spring wheat "Voronezh". The inventive compositions were studied as dressing agents for wheat seeds against the main pathogens of root rot diseases: Bipolaris sorokiniana (Helminthosporium sativum), Fusarium graminierum, Fusarium culmorum and fungi of the genus Penizillium spp. by known methods:

- Guidelines for state testing of fungicides, antibiotics and seed dressers for crops. M .: Kolos, 1985;

- Golyshin N.M. Fungicides in agriculture. M .: Kolos, 1970, p. 161-170.

The tests were carried out with artificially infected seeds of mixed infection. Infection was carried out in a vessel with a suspension of conidia and fungal spores, after which the grain was dried.

Seed dressing was carried out in round-bottom flasks semi-dry method according to the generally accepted method [Armor B.A. The methodology of field experience with the basics of statistical processing of results. M .: Kolos, 1979, 416 pp.] 2-3 days before germination.

Treated seeds with a certain flow rate were incubated in wet filters in Petri dishes at a temperature of t - 23-25 ° C.

The disinfecting properties of the preparations, as well as their effect on seed germination, were determined 7 days after germination.

The biological effectiveness of the fungicide (%) in the ratio of the prevalence of the disease in comparison with the control is calculated [Armor B.A. The methodology of field experience with the basics of statistical processing of results. M .: Kolos, 1979, 416 pp.] By the formula

,

,

where P and p are the prevalence of the disease, respectively, in the control and the experimental version.

The test results are shown in table.2-5.

From table 2 it is seen that all the mechanochemical complexes of TBA with polymers have 100% activity with a standard etching rate of 30 g / t of seeds and exceed that for a standard sample (TPS suspension concentrate tebuconazole), and the claimed compositions also exhibit high activity and on Penizillium spp.

To understand the essence of the claimed invention (the composition of complexes with the inclusion of polymers), we conducted laboratory tests of the preparations at rates lower than recommended, namely, the claimed mechanochemical complexes were tested at flow rates of 5 to 30 g / t, while the recommended rate of consumption of standard forms of tebuconazole and Raxil) is 30 g / t of seeds. It was shown that the proposed supramolecular complexes have 100% efficiency even in the norms of 10-15 g / t of seeds, in which a standard sample (TPS suspension concentrate) has lower efficiency (Table 3).

To confirm the obtained data on fungicidal activity, tests were carried out (Table 4-5) in comparison with the prototype drug Raksil, the results of which confirmed the high efficiency of the complexes we claimed.

Thus, the tests for fungicidal activity confirmed the high efficiency of the claimed complexes in comparison with analogues - suspension concentrate / TPS / tebuconazole and the well-known drug "Raxil".

The claimed technical solution allows to obtain preparations of tebuconazole with high solubility in water, increased fungicidal activity and low cost.

Table 1 The water solubility of tebuconazole (TBA) and its mechanochemical complexes with polymers obtained in grinders MAC-1-2 and AGO-2 under the following activation conditions (process module 1:24; activation time - 5 min; energy intensity 40 g) No. The composition of the mechanochemical complex (mass ratio) Solubility, mg / L (HPLC method) one TBK source substance 23 2 TBA: arabinogalactan = 1: 5 488 3 TBK: pectin = 1: 5 97 four TAC: polyethylene glycol = 1: 5 71 5 TBA: beta-cyclodextrin = 1: 1 528 6 TBA: polyvinylpyrrolidone = 1: 5 185 7 TBA-hydroxyethyl starch = 1: 2 356

Table 1a The dispersion of tebuconazole (TBA) and its mechanochemical complexes with polymers Sample name (type of grinder-activator) The maximum particle size (μm) in the selected fractions 25% fifty% 75% one hundred% TAC source sample 54.55 118.30 150.34 244.11 TBK-shredded MAC-1-2 16.54 27.59 38.87 87.07 TBK-AG (1: 5) - MAC-1-2 (57.5%) * 0,023 0,045 4.80 31.06 TBK-HEC (1: 2) - MAC-1-2 (41.6%) * 0,052 0.178 8.91 38,20 TBK-CD (1: 1) - MAC-1-2 2.10 4.20 7.48 25.27 TBK-AG (1: 5) - AGO-2 (96.5%) * 0,037 0,052 0,074 0.18 * - the content of nanofractions in the complexes

table 2 The fungicidal activity of tebuconazole (TBA) and its mechanochemical complexes with polymers A drug The consumption rate of the drug by AI, g / t Laboratory germination,% Microflora,% Helminthosporium spp + Fusarium spp. Penizillium spp. prevalence% efficiency% prevalence% efficiency% The control - 82.0 56.1 - 14.6 - Tebuconazole (60 g / L) TPS 30,0 97.0 2.1 96.3 2.1 85.6 (reference) Tbc-beta-cyclodextrin 30,0 95.0 0 100.0 0 100.0 (1: 1) TBA-arabinogalactan 30,0 90.0 0 100.0 0 100.0 (1: 5) TBK Pectin (1: 5) 30,0 93.0 0 100.0 2.1 85.6 TBK-hydroxyethyl starch 30,0 94.0 0 100.0 1,1 92.5 (1: 2) TAC-polyethylene glycol 30,0 92.0 0 100.0 3.3 77.4 (1: 5) Tbk- 30,0 95.0 0 100.0 0 one hundred polyvinylpyrrolidone (1: 5)

Table 3 The fungicidal activity of tebuconazole (TBA) and its mechanochemical complexes with polymers at lower flow rates Drug / passport substance The consumption rate of the drug by AI, g / t Laboratory germination,% Microflora,% Helminthosporium spp + Fusarium spp. Penizillium spp. prevalence% efficiency% prevalence% efficiency% The control - 65.0 66,2 - 16.9 - Tebuconazole (60 g / l) - TPS (reference) 5 78.0 7.0 89.4 6.4 62.1 10 89.0 3.4 94.9 6.7 60,4 fifteen 91.0 1,1 98.3 6.6 60.9 thirty 86.0 0 100.0 2,3 86.4 TBA-Betacyclodextrin (1: 1) 5 86.0 2,3 96.5 9.3 45.0 10 84.0 1,2 98.2 4.8 71.6 fifteen 90.0 1,1 98.3 6.7 60,4 thirty 86.0 0 100.0 2,3 86.4 TBK-hydroxyethyl starch (1: 2) 5 87.0 2,3 96.5 5.7 66.3 10 90.0 0 100.0 5,6 66.9 fifteen 92.0 0 100.0 3.3 80.5 thirty 85.0 0 100.0 4.7 72,2 TBA-arabinogalactan (1: 5) 5 86.0 5.8 91.2 9.3 45.0 10 89.0 2.2 96.7 5,6 66.9 fifteen 90.0 0 100.0 3.3 80.5 thirty 90.0 0 100.0 2.1 87.6 TBK Pectin (1: 5) 5 89.0 5,6 91.5 10.1 40,2 10 90.0 1,1 98.3 5,6 66.9 fifteen 86.0 0 100.0 4.2 75.1 thirty 82.0 0 100.0 2,4 85.8

Table 4 Fungicidal activity of TBA and its mechanochemical complexes with arabinogalactan and beta-cyclodextrin (repeated tests compared to the drug "Raxil" - as a reference) A drug The consumption rate of the drug by AI, g / t Laboratory germination,% Microflora,% Helminthosporium spp + Fusarium spp. Penizillium spp. prevalence% efficiency% prevalence% efficiency% The control - 72.0 43.1 - 12.5 - Raxil 60 g / l (reference) 30,0 90.0 2.2 82,4 2.2 82,4 TBA-arabinogalactan (1: 5) 10.0 85.0 5.9 86.3 6.3 49.6 15.0 80.0 3.8 91.2 3.8 69.6 30,0 89.0 0 100.0 0 100.0 TBA-Betacyclodextrin (1: 1) 10.0 88.0 3.4 92.1 2.2 82,4 15.0 90.0 0 100.0 1,1 91.2 30,0 86.0 0 100.0 0 100.0

Table 5 Fungicidal activity of TBA and its mechanochemical complexes with polyethylene glycol and polyvinylpyrrolidone (repeated tests as a reference compared to the Raxil preparation) A drug The consumption rate of the drug by AI, g / t Laboratory germination,% Microflora,% Helminthosporium spp + Fusarium spp. Penizillium spp. prevalence% efficiency% prevalence% efficiency% The control - 84.0 25.0 - 17.9 - Tebuconazole (60g / L) TPS 30,0 90.0 0 100.0 0 100.0 (reference) TAC-polyethylene glycol (1: 5) 10.0 85.0 8.2 67.2 3,5 80,4 15.0 89.0 3.4 86.4 2.2 87.7 30,0 93.0 2.2 91.2 1,1 93.8 TBA-polyvinylpyrrolidone (1: 5) 10.0 93.0 2.1 91.6 2.1 88.3 15.0 90.0 2.2 91.2 1,1 93.8 30,0 88.0 4,5 82.0 0 100.0

Claims (9)

1. A fungicidal agent comprising tebuconazole, characterized in that it additionally contains natural or synthetic water-soluble polymers in a mass ratio of tebuconazole: water-soluble polymers 1: (1-5), respectively, while it is obtained by mechanochemical interaction of tebuconazole and water-soluble polymers. 2. The fungicidal agent according to claim 1, characterized in that the water-soluble polymers are selected from the group: polyethylene glycol, polyvinylpyrrolidone, beta-cyclodextrin, arabinogalactan, hydroxyethyl starch, pectin. 3. The fungicidal agent according to claim 1, characterized in that it is presented in the form of a water-soluble powder. 4. The fungicidal agent according to claim 1, characterized in that the sizes of its particles are in the range of up to 10 microns. 5. The fungicidal agent according to claim 4, characterized in that the content of nanofractions is 41-96%. 6. A method of obtaining a fungicidal agent containing a fungicide and natural or synthetic water-soluble polymers in the ratio fungicide: polymers 1: (1-5), respectively, while mechanochemical interaction of tebuconazole and water-soluble polymers is carried out. 7. The method according to claim 6, characterized in that the water-soluble polymers are selected from the group: polyethylene glycol, polyvinylpyrrolidone, beta-cyclodextrin, arabinogalactan, hydroxyethyl starch, pectin. 8. The method according to claim 6, characterized in that the fungicidal agent is in the form of a water-soluble powder with a particle size of up to 10 microns. 9. The method according to claim 6, characterized in that the mechanochemical interaction is carried out in shock-abrasive devices.