CS252360B1 - Process for the Continuous Preparation of Water-Insoluble Salts of 1,2-Ethane-Bis-Dithiocarbamic Acid - Google Patents

Abstract

The solution relates to a method for the continuous preparation of water-insoluble salts of 1,2-ethane-bis-dithiocarbamic acid by reacting a water-soluble salt of 1,2-ethane-bis-dithiocarbamic acid with a water-soluble salt of manganese, zinc or copper in an aqueous medium at a temperature of 10 to 70 °C. Aqueous solutions of the reactants are simultaneously dosed into the reaction medium, consisting of the reaction product and the reactants, with a pH of 5.0 to 11.5, a water content of 52 to 87% by weight, while the average residence time of the reaction mixture in the reaction zone is 2.102 to 3.104 seconds and the intensity of mixing of the reaction mixture is characterized by the Reynolds criterion, for which ReM > 1.5 .103 K. The solutions can be used in connection with the industrial production of agrochemicals such as fungicides, fumigants, nematicides, dry seed dressings, nitrification inhibitors, rubber chemicals, human and veterinary therapeutics, inhibitors of microbial corrosion of metals, chemical reagents, etc.

Description

The invention relates to a process for the continuous preparation of water-insoluble salts of 1,2-ethane-bis-dithiocarbamic acid.

Several organic sulfur compounds containing the group:

N-C-S

II p

ranks among the traditionally produced and used agrochemicals such as many important fungicides (NABAM, AMBAM, MANEB, ZINEB, MANCOZEB, FERBAM, TERBAM, MARBAM, ZIRAM, PROPINEB, INTERNATIONAL, METIRAM, FORUM, MANZATE, NEMISPOR, DANDÁZEBE, ZIMAN, MANCOZAN, TRIZINAM, VONDOZEB, ZINAMIX, TURBO, KARAMATE, DICAMATE, KASCADE), fumigants (VAPAM), nematicides (MYLON), dry seed dressing (THIRAM and THIURAM). Some of these compounds have also found utility as nitrification inhibitors, antifungal fungicides, rubber chemicals, human and veterinary therapeutics, microbial metal corrosion inhibitors, chemical analytical reagents and the like.

Their main representatives are dithiocarbamidates (dithiocarbamates derived from hypothetical dithiocarbamic acid):

H 2-C-SH

II p

The replacement of the amino of the amino group with alkyl and of the dithiocarboxylic group with a metal usually has a significant effect on the agrochemical activity of these substances.

The most important dithiocarbamate-type fungicides are MANEB (manganese 1,2-ethane-bis-dithiocarbamate) (I)

S S

II II (—Mn — S — C — NH — CHa — CHa — NH — C — S “) (I)

ZINEB (Winter 1,2-ethanebisdithiocarbamate) (II)

S S

II II (—Zn — S — C — NH — CHa — CHa — NH — C — S—) _n (II)

MANKOZEB (zinc cation coordination compound with 1,2-ethanebisdithiocarbamate manganese) (III)

S S

II II (—Mn — S — C — NH — CHa — CHa — NH — C — S—) _n (Zn) _m (III)

With considerable simplification, it can be said that they are prepared in two stages. In the first reaction of 1,2-ethanediamine (ethylenediamine), carbon disulphide and the corresponding alkali (NH3, NaOH, KOH) in aqueous medium, the corresponding water-soluble salt of 1,2-ethane-bis-dithiocarbamic acid precipitates in the next step and / or zinc ion, most often an aqueous solution of sulfate or chloride.

WITH

NHa — CH2 — CHa — NHa + 2 CSa + 2 NH4OH — CHa — NH — C — S — NHd + HaO d

CH-NH-C-S-NHA

II p

WITH

II S

CHa — NH — C — S — NH4 S || n | + nZnCla— (—Zn — S — iC — NH — CHa — CHa — NH — C — S—) “+

CHa — NH — C — S — NH4 + 2 n NH4Cl

II p

2523G0

1,2-Ethane-bis-dithiocarbamic acid disodium salt (NABAM), the first of synthetically prepared bisdithiocarbamates, shoe first prepared in the laboratories of Rohm and Haas Co. in 1953 by HESTER. Several years later, HESTER and HILL (U.S. Pat. No. 2,317,765) as well as DIMOND, HEUBERGER and HORSFALL (Phytopathslogy, 1943, 33, 1095) have described the fungicidal properties of these compounds. These two have been of crucial importance for the development of 1,2-ethane-b's-dithiocarbamates as the most widespread fungicides of organic nature used in agricultural practice. MOREHART and GROSSAN (Agricultural Experiment) report on their development history

Station, University of Delaware 357, 1965).

Unlike NABAM, which is super-soluble in water, from which it can also be crystallized in the form of a defined compound (m.p. 80-81 ° C), the structure of MANEB, ZINEB and MANKOZEB is still fully elucidated. According to recent studies, these have a polymeric character, which explains their very poor solubility 'in water.

VONK (Decomposition of otf bisdittocarbamates and their metabolism by plants and microorganisms. Dissertation thesis, Utrecht, April 1975) assumes eg. for ZINEB, the following polymer-coordination structure:

After c - NH- CH / CH-NHί? -ΝΗ · /

-S • c x $ \ ψ · -Χ '·' χ X

X7 X c X ' ^AZ ' t

The preparation of metal salts of 1,2-ethane-bis-dithiocarbamic acid, in particular MANEB, ZINEB and MANKOZEB, has led to several scientific publications and patents. These include, for example: USA pat. no.

504 404, 2 855 418, 2 974 156 3 379 610

497,598, 3,856,836, 4,217,293, French Pat. no. 1 158 574 and 1 234 005, British Pat. no. 1,107,568, German Pat. no. 2,710,469 and Belgian Pat. no. The batch preparation methods described therein differ in the preparation conditions such as: the type of water-soluble salt of 1,2-ethanebisdicarbamic acid used as well as the type of water-soluble salt of manganese and / or zinc used for zincing, the order of addition of the reactants, their concentration, the pH of the reaction mixture, the temperature, the type of depressants and other additives used, the method of separating the reaction mixture, the method of drying the product and the like.

As reported by NEWSOME (Ethylenebsdithiccarbamates and Their Degradation Products-Analytical Methods for Pesticides and Floating Growth Regulators, Vod. XI, Asademic Press, Inc. 1980), 1,2-ethane-bis-dithiocarbamic acid derivatives are relatively unstable.

Among the degradation products were identified:

ethylene thiourea (C3HBN2S), ethylene urea (C3H6N2O),

2-imidazoline (C3H6N2), ethylene-thiurammonosulfide (C4H4N2S3), ethylene-bis-isothiocyanate (C4H4N2S), and some others. (LUDWIG, RA - THORN, GD - UNWIN, CH: Can. J. Bot. 1955, 33, pp. 42–59; CZEGLEDI-JANKO, G .: J. Chroraatog. 1967, 31, pp. 89-95) . As shown in his publications BONTOYAN and LOOKER (J. Agric. Food Chem. 1973, 21, pp. 338-341), MANEB appears to be less stable than zinc-containing products.

ENGST and SCHNAAK (Z. Lebenam.-U ders. Forsch. 1967, 134, pp. 216-221) as well as HYLIN (Bull. Environ. Contarn. Toxicol 1973, 13, 227-233) found that by decomposing MANEB in water almost all of the above compounds are formed.

Several of the by-products can be formed in the reaction mixture already in the preparation of the metal salts of 1,2-ethane-bis-dithicarbamic acid, especially when favorable conditions are created during the course of the side reactions. For example, THORN and LUDWIG (J. Appl. Chem. 1962, 12, p. 90-92) report that ethylene thiurammonosulfide and ethylene thiourea are formed by the action of atmospheric oxygen on an aqueous solution of NABAM in the presence of Nm ²⁺ -scalts (catalytic effect). The same substances have been identified in aqueous suspensions of MANEB and ENGST and SCHNAAK (Z. Lebenam.-Unters. Forsch. 1970, 143, p. 99). In addition, these authors have determined the presence of ethylene thiuram disulfide in the system.

The presence of ethylene urea in the reaction mixtures in the preparation of ZINEB, MANEB, and MANKOZEB has also been confirmed by BONTOYAN and spo252360 lupus (J. Ass. Offic. Anal. Chem., 1972, 55, p. 923).

In order to inhibit the formation of unwanted by-products in the process of producing dithiocarbamidates and to stabilize the reaction products, a number of compounds have been patented in the past period. These are in particular the following: sodium or calcium sulphite (U.S. Pat. No. 2,665,285), hexamethylenetetramine-upotropine (West Germany Pat. No. 1,113,607; U.S. Pat. No. 2,974,156; French Pat. 1,234,005), the addition of various metal salts (Dutch Pat. No. 288,639); 1,3,5-tris (cyanomethyl) hexahydrotriazine and / or dinitroso-pentamethylenetetramine (British Pat. No. 1,119,029), o-, m-, or p-phenylenediamine (French Patent No. 1,374,622), paraformaldehyde (French U.S. Pat. No. 1,344,342; U.S. Pat. No. 4,217,293, foirm.aldeh.yd (U.S. Pat. Nos. 3,856,836 and 4,217,293), as well as some others.

According to some overseas washing in sinah, to deepen the polymeric character of the metal salt structure of 1,2-ethane-bis-dithiocarbamic acid, especially MANEB, and thereby increase the stability of these compounds, it is recommended to use concentrated solutions of all reactants in their preparation.

It has now been found that the vast majority of the drawbacks of the above production methods can be overcome by the continuous preparation of water-insoluble salts of 1,2-ethane-bis-dithiocarbamic acid, in particular manganese, zinc and copper, by reaction of the water-soluble 1,2-ethane-bis-dithiocarbamide salt. acids with a water-permeable salt of manganese, zinc or medium in an aqueous medium at a temperature of 10-70 ° C according to the invention.

SUMMARY OF THE INVENTION The aqueous solutions of the reactants are simultaneously fed into a reaction medium consisting of the reaction products and the reactants, at a pH of 5.0 to 11.5, a water content of 52 to 87% by weight, the mean and of the reaction mixture in the reaction zone is 2. 10 ² to 3. ⁴ 10, the intensity of stirring, the reaction mixture is characterized by the Reynolds criterion which benefit

Re _{M =} n · d (D-d). p _{>1> g χθ3} Κ η 'where

Re _M is the Reynolds criterion for mixing

K is a coefficient dependent on the velocity distribution in the finger, the cross section between the vessel wall and the stirrer and in is the stirrer rotational frequency (s ^-1 J

D is the vessel diameter (m) d is the stirrer diameter-a (m) p is the density of the reaction mixture in the reaction medium (kg. M ^-3 ) η is the dynamic viscosity coefficient of the reaction mixture in the reaction medium (kg. M ^-1) .

. s- ¹ ) ·

For a power input of the stirrer (a) used per unit of volume of the stirrer (a) of the reaction mixture (N), N / V > 10 ² kg. m ^-1 . s ³ ). The agitated, non-agitated reaction mixture in the reaction medium is optionally carried out in such a way that dispersion of the solid, precipitation-forming particles in the reaction medium is also achieved in the reaction medium by homogenization. Substances which have surface-active activity and / or protective colloids and / or substances which increase the chemical stability of the product are also introduced into the reaction medium.

The following examples illustrate but do not limit the invention in any way.

Example 1

In order to carry out a laboratory study of the continuous process for the preparation of the 1,2-ethane-bis-dithiocarbamic acid manganese salt according to the invention, an all-glass apparatus consisting of two cascaded glass stirred reactors was stopped, the total volume of each being 1500 cm ³ (working - functional volume determined by the height of the side overflow of the reaction mixture was 1200 cm ³ ). The reactors were 120 mm in diameter, with the diameter of a two-leaf glass agar which was coaxially installed in each of the reactors was 55 mm. The stirrers were driven by electric motors with the set stirrer speed set to 900 rpm.

. min ^-1 . Both reactors were fitted with downstream coolers through which they were vented and glass mercury thermometers. The first of the above-mentioned reactor cascade members was provided with glass tubing feeds of reactants that resulted below the level of the reaction mixture in close proximity to the stirrer and an electrode steam (glass and saturated calomel electrode) to continuously register the pH of the reaction mixture.

The reactor located above was coupled to the second reactor cascade via a side overflow of the reaction mixture. A second stirred reactor was fed with an aqueous formaldehyde solution fed to the system to chemically stabilize the product. Both stirred reactors were operated at room temperature. The reaction product in the form of an aqueous slurry flowed free through the side overflow of the second reactor cascade member.

An average of 0.1728 g was fed to the first reactor cascade member by means of peristaltic metering pumps placed on weighing scales. s ^{-1 of} an aqueous solution of 1,2-ethane-bis-dithiocarbamic acid ammonium salt [C4HeN2S4 (NH4) 2] containing 39.62 wt. pen. active ingredient and an average of 0.1151 grams. s ^{-1 of} an aqueous solution of ammonium sulfate containing 13.26 wt. % M, n.

5 2 3 fi 9

During the precipitation, the temperature of the reaction mixture in the first reactor was from 27 to 29 degrees Celsius and the pH varied depending on the changes in the dosing amounts of the reacting solutions cd ranging from 7.2 to 8.8. A 37% aqueous formaldehyde solution was added to the reaction mixture, which had the character of a good flowing yellow suspension in the second mixed reactor, in an amount equal to 0.133 pot. parts by weight of HCOH per 100 wt. parts of the reaction mixture.

The average residence time of the reaction mixture in the stirred reactor cascade was 10.17. 103 seconds. The Reynolds criterion for mixing for the experimental conditions in the strokes of the cascade was close to:

Re _n.d _M (L - __ dj.p

7 <7). 0.055 (0.12-0.055). 1 220 = --------- ⁵ ---- = 1,557

0,042

The suspension of 1,2-ethane-bis-dithiocarbamic acid manganese salt in aqueous ammonium sulfate solution obtained as described above was worked up by decantation and subsequent dehydration into anhydrous MANEB, which was further used to prepare the zinc manganese salt 1,2-ethane-bis complex. -dithiocarbamide salt (MANCOZEB).

Example 2

The continuous process for the preparation of the zinc salt of 1,2-ethane-bis-dittocarbamiidic acid according to the invention was verified on a model apparatus using a pleasure flow reactor with a wing stirrer and a bench type dispersing stirrer placed on a common coaxial shaft assembly. The internal diameter of the rapid mixer was 125 mm and its volume after the reaction mixture was solved by the overflow was 7 560 cm ³ . To the bottom of the mixer, in close proximity to the binder, there were tubes serving to supply the reactants - an aqueous solution of sodium 1,2-ethane-bis-dithiocarbamate and an aqueous solution of sodium 1,2-ethane-bis-dithiocarbamate and an aqueous solution of ZnSO 2. The stirrer diameter was 85 mm, and they were rotated at 900 rpm. Electrodes for p-otentiometric sensing of the pH of the reaction mixture and a glass thermometer were installed in a rapid mixer near the overflow opening of the reaction mixture.

With the use of peristalic (hose) pumps from. Bachofen was dosed on average from 1.7901 g from polyethylene containers placed on the scales, using the built-in tube feeds into ¹ quick mixer. ^_1 of water, about 34.9 percentnébo solution of 1,2-ethane-bis-dithiocarbamate solution (C4H6S4N2Na2 J, prepared by dissolving 49.66% crystalline C4H6S4N2Naz. 6 H2 O 49.79% in distilled water, and stabilizing the so prepared, by addition of a solution of 0.55% water, about 37 ° / o solution of formaldehyde. the second inlet is dosed approximately 1 8713 g. of water, about 22 ^_1% ZnSO solution, prepared by dissolving 39.16 wt. parts of crystalline ZnSCh. 7 HZO 60, 84 parts by weight of distilled water.

At a temperature of the sodium salt solution of 1,2-ethane-bis-dithiocarbamic acid of 29 ° C and an aqueous solution of ZnSO _{4 of} 20 ° C, the temperature of the reaction mixture stabilized at 31 ° C. The pH of the reaction mixture varied between 5.0 and 7.5. The reaction mixture freely flowed through the overflow opening of the rapid mixer in the form of a fine cream-white suspension.

Subsequent treatment of the crude reaction product by decantation and dehydration (according to U.S. Pat. No. AO 243 558) yielded, on average, 0.07 g · s ^{-1 of the} anhydrous zinc salt of 1,2-ethane-bis-dittocarbamic acid.

Example 3

The continuous process for the preparation of the 1,2-ethane His-dithiocarbamic acid copper salt according to the invention has been verified on a miodel apparatus using a flooded flow reactor with a wing stirrer and a bench type dispersing stirrer placed on a common coaxial shaft. The apparatus used is described more closely in Example 2.

With the use of peristalic (hose) pumps from. Bachofen was dosed from an average of 1.1292 g from polyethylene containers placed on the scales into ¹ quick mixer. ^1, about 34.9% aqueous solution of ethane-1,2-bis-dithiocarbamate solution ( 'CdHsSáNzNazj stabilized by addition of formaldehyde. Preparing the solution dissolving 49.66 wt.% of the crystalline hexahydrate of 1,2-ethane-bis-dithiocarbamate in sodného- 49.75% by weight of distilled water and 0.55% by weight of about 37% by weight of aldehyde.

An average feed of 1.6486 grams was fed through the second separate feed. ^s-1, about 14.9% aqueous solution of CuSO ;, připraveného- dissolving 23.31 wt. pen. CuSO-j. 5 H2O in 76.03 wt. % of distilled water, with 0.66 wt. % crystalline urotroipis, nu. The pH of the reaction mixture varied between 7.2 and 8.8 during the precipitation reaction. The reaction mixture freely flowed from the flow reactor through the overflow opening in the form of a fine cream-pale brown suspension in an amount of 2.7778 g. s ^_I .

The crude reaction product was further worked up by decanting and dewatering as described in U.S. Pat. AO 243 558, with 0.5 wt.

parts of urotropin and 2.5 wt. parts by weight of calcium lignosulfonate in the form of so-called. thickened sulphurous stillage.

Example 4

A continuously operating stirred reactor was used to prepare the stabilized 1,2-ethane-bis-dittocarbamic acid manganese salt as its aqueous suspension. The reactor consisted of a standing vacuum vessel for the ratio of height (4) to its diameter (Dj applied: H / D - 1.1, fitted with a turbine stirrer with straight perpendicular blades and a separating disk, for which: D / d = 3.1.

The stirrer was placed centrally in the reactor, and the reactor was provided with baffles. The reactor had a domed bottom and was provided with an overflow at a height of 420 dm ^{3 of the} reaction mixture dropping. Into the reactor at the height of the turbine stirrer, the inlets of the reactants - a 35% aqueous solution of 1,2-ethane-bis-dithiocarbamic acid disodium salt, prepared by homogenization of 48.72 wt. parts by weight of water, 49.66 wt. parts by weight of crystalline disodium salt (CdHeN / SiNaO, 6H2O), 1.07 wt. parts of NaOH with 0.55 wt.

parts of 37% methanol and an aqueous MnSCU solution containing 14.0% Mn (38.5% MnSO ₄ ) and 1.0% calcium lignosulfonate solids. The reactor was fed on average per minute using PAX piston metering pumps: 4.675 kg of aqueous disodium salt solution (C4HeN2S4Na2.6 H2O) and 2.5 kg of aqueous MnSCU solution.

During the precipitation reaction, the temperature of the reaction mixture was maintained between 28-33 and the pH of the reaction mixture varied between 9.6 and 10.8. Under these conditions, an average of 7175 g of a fine slurry of a bright yellow color was produced per minute, which continuously discharged from the reactor through the overflow. In order to stabilize the suspension, for each mole of the manganese salt contained in the suspension! adds 5 more after the overflow. 10 ^-2 mol of urotropin [approximately 45 g (CH2) 6N4. . min ¹ ].

Under these conditions, the mean residence time of the reaction mixture in the reaction zone was 4.355. 10 ³ seconds (72.58 minutes), with the mixing intensity characterized by the Reynolds criterion:

ReM__n. d (D-d). p __

4.75. 0.26 (0.80 - 0.26). 1,240 ^- 5.7. IO ² ~ ⁴

The crude suspension was wet-milled using a Fryma-type colloid mill using carburetor grinding wheels and wet cake was decanted and filtered

Re _M = 1.45. 10 ⁴ K dries in the manner of MS. AO 243 558 to a finely dispersed 1,2-ethane-bis-dithiocarbamic acid manganese salt (MANEB).

Claims (2)

SUBJECT 1. A process for the continuous preparation of water-insoluble salts of 1,2-ethane-bis-dithiocarbamide acid by reacting a water-soluble salt of 1,2-bis-dithiocarbamide with a water-soluble salt of manganese, zinc or medium in an aqueous medium at 10 to 70 ° C. The reaction medium is added simultaneously to the reaction medium consisting of the reaction product and the reactants, at a pH of 5.0 to 11.5, a water content of 52 to 87% by weight, the mean residence time of the reaction mixture in the reaction zone being 2. . 10 ² to 3. ⁴ 10, the intensity of stirring, the reaction mixture is characterized by the Reynolds criterion which benefit Re _M __n. d (D-d), p > 1.5. 10 ³ YNÁLEZU where Re _M is Reynoldsavo's criterion for mixing K is a coefficient depending on the velocity distribution in the annular cross section between the vessel wall and the stirrer n is the rotational speed of the stirrer ( ^s1 ) D is vessel diameter (m) d is stirrer diameter (m) p is density of the reaction mixture in the reaction medium (kg. M ³ ) η is the dynamic coefficient of viscosity of the reaction mixture in the reaction medium. 2. The method of claim 1, wherein one or more of the chemical stability enhancing agents, protective colloids, and surfactants are added to the reaction medium.