CS218084B1 - Method of making the complex manganese-zincate salts of the ethalenebisditiokarbamide acid - Google Patents

Description

SUMMARY OF THE INVENTION The present invention provides a process for preparing a complex manganatosinium salt of ethylenebisdithiocarbamic acid by reacting an ammonium salt of ethylenebisdithiocarbamic acid with manganese and zinc salts of inorganic acids.

Dithiocarbamide fungicides remain an important and irreplaceable site in modern phytopharmacology. Depending on the presence of metals in the molecule, not only their biological but also chemical properties change. A distinctive and undesirable feature is their reduced. stability, whereas less stable compounds often have more desirable biological properties. .

An increase in the stability of dithiocarbamide fungicides has been the subject of several patents. It is known e.g. a method of increasing the stability of maneb by urotropin (U.S. Pat. No. 2,974,156), Cu ¹ compounds (DAS 1,793103), 1,8-3,6-diendomethylene-1,3,6,8-tetraaza-cyclodecane (DAS 1,593.282), or alkanolamines (French Pat. No. 2,071,293). The formation of mancozeb-manganatosinium complex of ethylenebisdithiocarbamic acid was also due to its increased. stability while improving biological expression. But even in this case, the stability issue remains at the forefront. Increased mancoseb stability is achieved, for example, by urotropin (British Pat. No. 1,000,137, DAS 1,234,704, French Pat. No. 1,326,689), or by a different method of adding water-soluble manganese and zinc salts to an aqueous solution of ethylenebisdithiocarbamic acid (U.S. Pat. No. 3,869,486). However, the processes described do not adequately ensure the stability of the mancozeb-based formulations.

Now . It has been found that the complex manganatosinium salt of ethylenebisdithiocarbamic acid with high stability can be prepared by ammonium reaction. salts of ethylenebisdithiocarbamic acid with manganese and zinc inorganic salts. acids in an aqueous medium, according to the method of the invention. invention. .......

The essence of the invention is that. the reaction takes place at. temperatures of 20 to 50 ° C with successive mixing of the individual reaction components over a period of more than 30 minutes. The resulting product, of which more than 50% by weight consists of particles larger than 40 microns, is separated from the mother liquor by filtration, suspended in water and suspended, and subjected to wet grinding to a particle size of up to 32 microns in at least 60% by weight. The product thus obtained is spray dried to a substrate with a water content of up to 10% by weight, and then vacuum dried under stirring at a vacuum of 0.133 to 4.0 kPa and a temperature not exceeding 100 ° C to a product with a water content of 0.2 to 2.0%. wt.

According to the invention, a product with a high active ingredient content in the range of up to 95% of theory is obtained. *

The process according to the invention in combination with a process for the preparation of an ammonium salt of ethylene-bis-dithiocarbamic acid protected by the invention. author's certificate no. 197.196 ensures a high quality mancozeb-based product with a low ethylene thiourea content of 0.1%.

Several criteria can be used to assess the stability and quality of a preparation with respect to the content of ethylene urea (ETU).

According to the latest FAO recommendation (Specification 31/1 / S / 8 of 3.6.1979) for mancozeb technical, the active substance content must be at least 85% and the ETU content should not exceed 0-5% (limit content. ETU not yet established).

For the final formulation - dispersible powder - according to. FAO (Specification 34/3 / S / 8 of 05.06 .: 1979). applies to stability in accelerated storage tests (storage for 14 days at 54 ° + 2 ° C, comparable storage test for 2 years at normal temperature) that the content of active substance must not be less than 90% of the original content. ETU content not determined.

Some products available on the market for various foreign companies have certain parameters declared. So eg. for mancozeb-based preparation marked POLICAR MZ, stability is declared such that a max. 2.5% loss of active substance content for 12 months of storage at normal temperature, for NEMISPOR the ETU content is limited to max. to 0.3%.

In fact, for different mancozeb-based formulations, the decrease in the active substance content during the abovementioned accelerated storage tests ranges from 3.4 to 8.5%, with an ETU content of from 0.08 to 1.3%. The decrease in the active substance content of the preparation according to the invention did not pass through the accelerated. storage tests

3.3% at the present .ETU content up to 0.2-%, which is clearly below the average of most known formulations available on the market.

. . The method of the invention illustrates but does not limit the following. example.

Example

250 kg of enamelled boilers with anchor stirrer, equipped with a thermometer and a heating jacket, were charged with 75 kg of water, 49.3 kg

37.5% of ammonium salt, ethylenebiss dithiocarbamic acid, and the temperature of the boiler contents were. The boiler was adjusted to 30 ° C by a hot-water circuit into the jacket. From the measuring cups are then added sequentially with stirring for 1.5 hours a solution of 49.6 kg broad, so the manganese-zinc containing increased anti- 10.2 kg and 2.15 kg MnSO4 ZnSO _fourth The contents of the reaction boiler were stirred at 30-35 ° C for a further 2 h and then filtered on a centrifuge and washed with 250 L of cold water on the filter. 30 kg were obtained. wet cake with a dry matter content of 65%. The particle size product had the following screen analysis:

Sieve size in mm Sieve residue in%

0,1250,55

0,06313,09

0.04045.68 ________ 0.032 12.25 Total

71,57

40 kg of water was added to the wet cakes and the resulting aqueous suspension was ground with stirring in a vertical bead mill. The ground aqueous suspension exhibited the following particle size composition in a sieve analysis:

Sieve size in mm Site Remain% 0,125 0.07 0,063 0.82 0,040 10.22 0,032 12.09 Together 23.20 SUBJECT

Claims (1)

40 kg of water was added to the wet cakes and the resulting aqueous suspension was ground with stirring in a vertical bead mill. The ground aqueous suspension exhibited the following particle size composition in a sieve analysis: Sieve size in mm Site Remain% 0,125 0.07 0,063 0.82 0,040 10.22 0,032 12.09 Together 23.20 SUBJECT The thus prepared aqueous mancozeb suspension was spray dried in an oven to obtain 17.4 kg of technical mancozeb containing 89.4% active ingredient, 0.1% ethylene thiourea and 5.2% water and then dried with stirring over a period of 5 hours. h under a vacuum of 1.33 kPa and a temperature of 70 ° C. 16 kg of mancozeb were obtained, which showed an active ingredient content of 92.7%, ethylene thiourea of 0.1% and water of 0.6%. INVENTION Process for producing a complex manganatosinium salt of ethylenebisdithiocarbamic acid with high stability by reacting an ammonium salt of ethylenebisdithiocarbamic acid with manganese and zinc salts of inorganic acids in an aqueous medium, characterized in that the reaction takes place at temperatures of 20 to 50 ° C with successive mixing minutes, and the resulting product having more than 50% by weight of particles greater than 40 microns is separated from the mother liquor by filtration, suspended in water to a suspension and subjected to wet grinding to a particle size of up to 32 microns in at least 60% by weight the product is spray dried on a substrate with a water content of up to 10% by weight and then vacuum dried under stirring at a temperature not exceeding 100 ° C and a vacuum of 0.133 to 4.0 kPa to a product with a water content of 0.2 to 2.0% by weight h.