CS239198B1 - Combined herbicide's stable water suspension production method - Google Patents

Abstract

The subject of the invention is a method of production of the combined herbicidal formulation in aqueous suspension based on 2-methyl-4-chloro- -phenoxyacetic acid and N, N‘-dimethyl-N‘- - (4-isopropylphenyl) urea. The preparation contains one active substance (MCPAi dissolved in water and into this solution the second active ingredient (isoproturon), which is insoluble in water, stabilizes via surfactants, polysaccharide, ethylene glycol and dimethylformamide to a stable aqueous suspension.

Description

The invention relates to the production of a herbicidal suspension.

According to dosia! In the known and well-established process, 2-methylphenoxyacetic acid (ΜΌΡΑ) is formulated as a water-soluble sodium, potassium or dimethylamine salt. These solutions are used as herbicidal compositions.

The N, N‘-dimethyl-N- (4-isopropylphenyl) -urea is formulated as a herbicidal preparation as a wettable powder or an aqueous suspension.

The use of the active ingredient combination in agriculture requires subsequent application of the MCPA salt solution and the species by application of the herbicidal product with isoproture (N, N‘-dimethyl-N‘- (4-isopropylphenyl) -urea).

The disadvantage of dosia! The manufacturing process used is the necessity of subsequent application of individual preparations. Another disadvantage is the handling of pesticidal powders.

We have found that it is possible to prepare a lierbicidal formulation based on MCPA and isoproture in the form of a stable aqueous suspension. The new form of the combined herbicidal formulation contains one water-soluble active ingredient (MCPA) and into this solution the other water-insoluble active ingredient (isoproturon) is stabilized by means of surfactants, polysaccharide and dimethylformamide to a stable aqueous suspension.

The present invention relates to the production of a combination herbicidal composition comprising 2-methylphenoxyacetic acid (MCPA) and N, N'-dimethyl-N '- (4-isopropylphenyl) urea, which is prepared from an aqueous solution of sodium, potassium, or a dimethylamine salt of 2-methyl-4-chlorophenoxyacetic acid To a 12-40% ⁷ aqueous MCPA salt solution is added a finely milled active ingredient N, N'-dimethyl-N '- (4-isopropylphenyl) -urea with stirring. The amount of finely divided active ingredient is selected such that the resulting product contains 5 to 40% active ingredient in the form of a suspension. reaches the desired fineness.

If the active substance is sufficiently finely ground in the solid phase, it is sufficient to add to the fluidized suspension the stabilizing components: polysaccharide in an amount of 0.1 to 5% by weight. and 0.1 to 4% formaldehyde based on the final product.

When finalization is complete, the suspension is diluted with water and ground by wet grinding to ensure product homogenization.

The process can be modified by adding N, N‘-dimethyl-N- (4-isopropylphenyl) urea as a dispersible powder to the MCPA salt solution.

If all the components of the finalization are of the desired fineness, then the milling process can be omitted.

It is advantageous to dissolve the polysaccharide into formaldehyde in advance and add it before or after grinding with stirring.

The following examples illustrate the invention.

Example 1

50 ml of a 2-methyl-4-chlorophenoxyacetic acid sodium salt solution containing 32.3% MCPA of 88.47% purity was added to the three-necked flask reaching the stirrer and thermometer, the pH of the solution being 7.8 and the solution contained 8 θ / ο wt. ethylene glycol. 50 ml of a stable aqueous suspension of N, N'-di, methyl-N '- (4-isopropylenephenyl) -urea containing 25 g of the active ingredient, 1.1 g of a nonionic surfactant which is a mixed copolymer of propylene oxide and ethylene oxide, were added with stirring, 1.5 g of ethylene glycol 0.25 g of polysaccharide (Rodopol) and 0.1 ml of formaldehyde were added with stirring, and after 40 minutes of stirring, an aqueous suspension was obtained whose 1% solution had a 99.4% suspension stability after 30 minutes and The 5% solution had a 98.6% suspension stability.

Example 2 ml of a 2-methylphenoxyacetic acid sodium salt solution containing 20.1% MCPA was dispensed into a flask. MCPA sodium salt solution was prepared from technical sodium salt of MCPA, which was 88.47% pure, contained 70.04% MCPA, 1.94% o-2-methylphenoxyacetic acid, 4.5% 2-methyl-6- chloro-phenoxyacetic acid acid and 2.75% 2-methyl-4, ^l 6-dichlorophenoxyacetic acid, dissolved in water to a saturated solution at 5 ° C.

4 ml of ethylene glycol, 0.5 ml of formaldehyde and 1.3 g of Rodopol (polysaccharide) were added to said Na salt solution. Next, 20 ml of an aqueous suspension of N, N‘-dimethyl-N- (4-isopropylphenyl) urea prepared from 10 g of the active ingredient and water was added to the solution. Furthermore, 0.5 wt. a non-ionic surfactant which is a mixed copolymer of propylene oxide and ethylene oxide of the formula:

(C2H4O) _x - (CsH5O4) - (C2H4O) _x- H, wherein the polyoxypropylene chain forms the hydrophobic and polyoxyethylene chain hydrophilic portion of the molecule, and 0.2 percent by weight of a nonionic emulsifier was added. blender with ballutina.

The resulting product, after separation from the glass beads, contained the desired ratio of active ingredients and the 1% solution had a 99% aqueous suspension after 30 minutes.

Claims (2)

SUBJECT 1. A process for the preparation of a stable aqueous suspension of a combination herbicidal preparation based on the active ingredients 2-methyl-4-chlorophenoxyacetic acid and N, N'-dimethyl-N '- (4-isopropylphenyl) urea, characterized in that 4-Chloro-phenoxyacetic acid containing 12 to 40% by weight of the active ingredient is added, with stirring at room temperature, N, N'-dimethyl-N '- (4-isopropylphenyl) urea in an amount of 10 to 30% by weight. 0.5 to 4.2% by weight of a nonionic surfactant, which is a mixed copolymer of propylene oxide and ethylene oxide, 0.1 to 0.8% by weight of a nonionic emulsifier of the invention made by the exyetylation of higher fatty alcohols, 5 to 12% by weight of ethylene glycol 0.1 to 4% formaldehyde, the final blend is ground by wet grinding, finally 0.1 to 5% polysaccharide is added with stirring and diluted with water so that the product contains 40 to 50% by weight of active ingredients and homogenized . 2. The method of claim 1, wherein the polysaccharide addition process is carried out. and combining the dilutions with water and the poilysaccharide is previously dissolved in water and formaldehyde and then added to the final mixture.