RU2408188C1 - Herbicide agent - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to agriculture. The herbicide agent contains an active substance or chemical modification thereof and a surfactant. The active substance is aryloxycarboxylic acid, 3,6-dichloropyridine-2-carboxylic acid or 2-methoxy-3,6-dichlorobenzoic acid. The chemical modification of the active substance is in form of esters of these acids having normal and isomeric structure. The surfactant is a trialkylamine salt containing one alkyl radical with not less than 8 carbon atoms. The salt is synthesised from the corresponding tertiary alkylamine and the said acid.

EFFECT: invention increases concentration of active substance in the herbicidal preparation.

3 cl, 3 ex, 2 tbl

Description

The invention relates to the field of production of herbicidal preparations, namely to agriculture, and is used in the fight against weed vegetation in crops of cultivated plants.

A prerequisite for creating preparative forms of herbicides in the form of emulsion concentrates is the solubility of the active substance of the herbicide or its chemical modification in an organic solvent and the presence of surface-active compounds in its composition. The latter is necessary to create an emulsion of the working fluid (the preparation is diluted with water at the rate of 100-300 l of water per 1 ha) with a droplet size of 1-3 microns.

For example, the well-known drug Esteron, CE (564 g / l 2,4-di-chlorophenoxyacetic acid in the form of 2-ethylhexyl ether) has the above-mentioned indicators of the quality of the working fluid emulsion (Handbook of pesticides and agrochemicals approved for use in the Russian Federation , M: Agrorus, 2008.S. 153).

Based on the calculation that the company used 100% 2-ethylhexyl ether (theoretically possible) in the production of Esteron containing (excluding solvent and surfactant) 726 g / l 2,4-D acid, the required volume of ether to create the drug " Esteron "makes 773 ml. The density of the ether is 1.1 g / cm ³ . This means that to obtain a high-quality working solution, it is possible to add up to 1 liter of 227 ml of surfactant to the taken ether (provided that the density is close to unity).

Thus, the quality of the working fluid, requiring the presence of a surfactant in the preparation, is that limiter for increasing the concentration of the active substance in the preparation.

Considering the obvious fact that the technical 2-ethylhexyl ester of 2,4-dichlorophenoxyacetic acid (2,4-D acid) (63-64%) does not correspond to the theoretical (66.3%), the restrictions on the possibility of increasing the concentration of the active substance of the herbicide in the preparation is even tougher and require the use of more effective surfactants to ensure the quality of the emulsion of the working solutions at the level of 1-3 microns.

Similar calculations performed for 2-ethylhexyl ester of 2-methoxy-3,6-dichlorobenzoic (dicamba), 3,6-dichloropyridin-2-carboxylic (clopyralide) acids confirm the above pattern.

In order to eliminate restrictions on increasing the concentration of the active substance in herbicidal preparations, we offer a new technical solution.

The essence of this proposal is as follows:

- surface-active substances (surfactants) used in the manufacture of the drug should be synthesized on the basis of the active substance of the drug (if the active substance is 2,4-D, then the surfactant must be based on 2,4-D);

- the synthesized surfactant must be dissolved in the ester of the corresponding acid used to obtain the drug.

Based on the structural features of the molecules of 2,4-dichlorophenoxyacetic, 3,6-dichloropyridin-2-carboxylic, 2-methoxy-3,6-dichlorobenzoic acids, a convenient variant of the modification of these active ingredients of herbicides is the synthesis of water-soluble amine salts, the biological effectiveness of which is well known .

The drug "Dikopur F" - an aqueous solution of dimethylamine salt of 2,4-D acid (Handbook of pesticides and agrochemicals approved for use in the Russian Federation, M: Agrorus, 2008, p. 152).

The Referee preparation - water-dispersible granules of dicamba diethylethanolamine salt (Handbook of pesticides and agrochemicals approved for use in the Russian Federation, M: Agrorus, 2008, p. 185).

The drug "Lontrel-300" is an aqueous solution of clopiraralide monoethanolamine salt (Handbook of pesticides and agrochemicals approved for use in the Russian Federation, M: Agrorus, 2008, p. 195).

The biological effectiveness of the amine salts of 2,4-D, dicamba, and clopyralide indicates the need for more extensive studies on the synthesis and study of the physicochemical properties of amine salts and the detection of the possible presence of surface-active properties in certain structures of amine salts.

Indeed, in the course of the study, it was established that only certain structures of the amine salts of aryloxycarboxylic acids (2,4-D acid, cresoxyacetic, 2M-4X), derivatives of pyridinecarboxylic, benzoic acids (3,6-dichloropyridin-2- carboxylic acid, 2-methoxy-3,6-dichlorobenzoic acid), namely, trialkylamine. In this case, the tertiary alkylamine used for salt synthesis should contain one alkyl radical with the number of carbon atoms of at least 8. It is these tertiary amine salts, which possess surface-active properties and solubility in organic matter, that satisfy all the requirements of this invention.

The herbicidal agent contains the above-mentioned acids as an active substance, chemical modification of the active substance in the form of esters of these normal and isostructural acids, and as a surfactant it contains a trialkylamine salt containing one alkyl radical with at least 8 carbon atoms synthesized from the corresponding tertiary alkylamine and this very same acid.

The herbicidal agent may further comprise an organic solvent or a mixture thereof.

The physicochemical properties of the amine salts of 2,4-D acid, dicamba, and clopyralid are presented in Table 1.

Table 1 The surface tension of 2% aqueous solutions of amine salts of 2,4-dichloro-phenoxyacetic, 3,6-dichloropyridin-2-carboxylic, 2-methoxy-3,6-dichlorobenzoic acid and solubility in organic and water 2-methoxy-3,6-dichlorobenzoic acid salt The surface tension at the liquid-air interface, mN / m Solubility g / 100 mg paraffin aromatics H ₂ O one 2 3 four 5 isopropylamine 69.8 1,1 1.9 > 100 triethanolamine 65.1 1.8 2,4 > 100 diethylamine 68.3 2.2 3,1 > 100 dimethylalkyl (C ₉ -C ₁₂ ) amine 30.5 > 100 > 100 > 100 methylethylalkyl (C ₁₀ -C ₁₄ ) amine 29.8 > 100 > 100 > 100 2,4-Dichloropheno-acetic acid salt isopropylamine 64.5 1,2 1,5 > 100 triethanolamine 67.3 1.7 2.2 > 100 diethylamine 69.1 2.1 2.5 > 100 dimethylalkyl (C ₉ -C ₁₂ ) amine 31.5 > 100 > 100 > 100 methylpropylalkyl (C ₉ -C ₁₂ ) amine 31.8 > 100 > 100 > 100 3,6-Dichloropyridin-2-carboxylic acid salt isopropylamine 70.5 0.8 0.75 > 100 triethanolamine 64.8 1,5 0.95 > 100 diethylamine 69.1 0.9 0.8 > 100 dimethylalkyl (C ₉ -C ₁₂ ) amine 32.1 > 100 > 100 > 100 methylisopropylalkyl (C ₉ -C ₁₂ ) amine 32,4 > 100 > 100 > 100

The possibility of increasing the concentration of active substances of the herbicidal preparations according to the invention is illustrated by the following examples.

Example 1

100 g of technical 2-ethylhexyl ester of 2,4-D acid, containing 60 g in terms of 2,4-D acid, is placed in a flask, then the calculated amount of dimethylalkyl (C ₁₀ -C ₁₄ ) amine and technical 2 are added to it. 4-D acid.

Within 1 hour at room temperature, the reaction mass turns into a homogeneous liquid from yellow to light brown in color. The obtained samples are analyzed for the content of 2,4-D acid, the quality of the working fluid (surface tension, stability, droplet size of the emulsion).

Example 2

100 g of technical 2-ethylhexyl ester of 2,4-D acid containing 64 g in terms of 2,4-D acid, are placed in a flask, technical 2,4-D acid and the calculated amount of dimethylalkyl are added (C ₁₀ -C ₁₄ ) amine and 15 g of solvent - nefras. The resulting mixture was stirred at room temperature until a homogeneous mass.

Example 3

100 g of technical 2-ethylhexyl ester of cresoxy acetic acid containing 60 g in terms of cresoxy acetic acid is stirred into a flask, a calculated amount of technical cresoxy acetic acid and a calculated amount of dimethylalkyl (C ₉ -C ₁₂ ) amine are added, and mixed until a homogeneous mass is obtained.

Summary results are presented in table 2.

The lower limit of the decrease in the concentration of dimethylalkylamine salt of 2,4-D acid is limited by its surface-active properties, which affects the technical characteristics of the working fluid.

Absolutely identical results were obtained for preparations based on dicamba and clopyralide in the form of emulsion concentrates based on 2-ethylhexyl ethers (Vigosuron, CE based on dicamba 2-ethylhexyl ether and Efilon, CE based on clopiraralide 2-ethylhexyl ether).

The proposed solution allows to increase the concentration of the active substance in the herbicide preparation, as well as its biological effectiveness.

table 2 Indicators of the working fluid of herbicidal preparations based on 2,4-D acid No. p / p Sample, composition Density,
g / cm ³ Fluid characteristics The concentration of the active substance, g / l Stability The size of the droplets of the emulsion of the working fluid, microns The surface tension at the liquid-air interface, mN / m one. 100 g tech. 2,4-D acid ester + 42 g of dimethylalkylamine salt (DMAA salt) 1.15 homogeneous coagulate is absent monodisperse, less than 1 micron 30.8 639 2. 100 g tech. 2,4-D acid ester + 32 g DMAA 2,4-D salts 1.3 - "- - "- 29.9 633 3. 100 g tech. 2,4-D acid ester + 22 g DMAA 2,4-D salts 1,11 - "- - "- 30.1 627 four. 100 g tech. 2,4-D ether + 12 g of DMAA 2,4-D salt 1.09 - "- 2-5 microns 38,4 622 5. Esteron (prototype) 1.09 - "- 1-3 microns 30.5 564 6. 100 g tech. ether 2,4-D + 60 g DMAA salts 2,4-D + 15 g nephras example 4 1.12 homogeneous coagulate is absent monodisperse less than 1 micron 30.8 600 7. 100 g tech. Cresoxy acetic acid ester + 49 g DMAA of the Cresoxy acetic acid salt Example 3 1.14 - "- - "- 31.9 630

Claims (3)

1. A herbicidal agent containing the active substance or its chemical modification and surfactant, characterized in that the active substance is aryloxycarboxylic acid, 3,6-dichloropyridin-2-carboxylic acid or 2-methoxy-3,6-dichlorobenzoic acid , the chemical modification of the active substance is an ester of these acids of normal and isostructure, and as a surfactant it contains a trialkylamine salt containing one alkyl radical with the number of atoms carbon of at least 8, synthesized from the corresponding tertiary alkylamine and this very same acid. 2. The herbicidal agent according to claim 1, characterized in that it further comprises an organic solvent or a mixture thereof. 3. The herbicidal agent according to any one of claims 1 or 2, characterized in that it is presented in the form of an emulsion concentrate.