CS237725B1 - Preparation method of salt solutions of alkylenbisditiocarbamide acids and equipment to perform this method - Google Patents

Abstract

The invention relates to a process for preparing solutions salts of alkylenebisdithiocarbamic acids by reacting carbon disulfide, alkinediamines with 2 to 6 carbon and ammonia and / or hydroxide alkali metal and / or hydroxide alkaline earth metal at 20 to 60 ° C and at pH 7.5 to 13.0. alkane, carbon disulphide and / or a mixture thereof and ammonia and / or an alkali metal hydroxide and / or the alkaline earth metal hydroxide is continuously dosing into the circulating reaction environment that is a mixture of product intermediates and reactants. Mass flow rate of circulating reaction the mixture is 50 to 3,000 times by weight carbon disulphide dosing rate. Solutions of the salts of said acids may be present prepare for the equipment that it consists of from the reaction mixture reservoir, circulating pumps, heat exchanger, alkanediamine feed, carbon disulphide feed ammonia and / or alkali hydroxide metal and / or alkali metal hydroxide soil, draining the raw product and falls static mixer.

Description

BACKGROUND OF THE INVENTION The present invention relates to a process for the preparation of solutions of alkylene bisdithiocarbamic acid salts and to a process for carrying out this process.

Water-soluble salts of substituted dithiocarbamic acids are important intermediates and products of the chemical industry. Based on them, the production of several agrochemicals is based - fungicides, other disinfectants, seed globes and nitrification inhibitors; industrial fungicides; rubber chemicals; pharmaceuticals; metal microbial corrosion inhibitors; chemical analytical reagents and the like.

Water-soluble salts of substituted dithiocarbamic acids are usually prepared! by reacting carbon disulphide with alkanediamines or dialcanamines in an alkaline medium.

Xlasia processes for preparing water-soluble salts of alkylene bis-dithiocarbamic acids were based on the reaction of carbon disulfide with alkanediamines in a strong alkaline environment. According to processes of this kind, for example, the disodium salt of ethanebisdithiocarbamic acid was prepared by adding carbon disulfide to a mixture of 1,2-ethanediamine and aqueous NaOH with stirring.

Processes of this kind get used to! U.S. Pat. 2 317 765 and 2 504 404, MS. AO č. 197, 96.

U.S. Pat. No. 2,693,485, French patent no. 1,158,574; 1 08, 446 and Zevizion et al. (Chim. Prom. 3, pp. 174-175 (1972)), the water-soluble salts of bisdithiocarbamic acids prepared by these strongly alkaline processes are usually characterized by: low purity - I contain! other by-products contaminating the main product, the desired product yields are low, aqueous solutions of alkali salts are relatively unstable, solid crystalline products isolated from the reaction mixture upon cooling are difficult to dissolve in water, solutions usually smell strongly of releasing hydrogen sulfide, and they also contain thiocarbonates.

U.S. Pat. No. 2,693,485 also discloses that fungicides prepared by this method tend to be phytotoxic, which reduces their agrochemical value.

A more recent and substantially improved process for the preparation of water-soluble, in particular sodium salts of alkylenebisdithiocarbamic acids is protected by U.S. Pat. This method of preparation is the opposite of the so-called conventional method. strongly alkaline process. Accordingly, the corresponding alkanediamine (e.g., 1,2-ethanediamine) reacts first with the carbon disulfide to form an intermediate which is reacted with the appropriate hydroxide solution in a subsequent step.

Although this process represents some improvement, especially as regards the formation of unwanted intermediates, stability and phytotoxicity, its use does not sufficiently prevent the formation of by-products which can be judged in aqueous solutions of alkylene bis-dithiocarbamic acids due to the dark orange color of the solution and that solutions (mainly sodium and potassium salts) usually smell quite strongly of hydrogen sulfide.

The effect of the basic reaction conditions on the yield and purity of the 1,2-ethanebisdithiocarbamic acid diammonium salt prepared according to U.S. Pat. No. 2,609,389 has been studied in detail by Zavizion et al. (Chim. Prom. 1972 (3), pp. 174-75).

_t To suppressors freer vedTajřích products designed Gobell _(T pa tent US 2,693,485 6) to proceed to the preparation of the water-soluble metal salt of the title alkylénbisditiokarbamidovej of a batch process such that the reaction pH maintained in the range of 8.5 to 11, 0 is preferably in the range of 9.0 to 10.5. As the author states, the aqueous solutions of 1,2-ethenebisdithiocarbamic acid disodium salt prepared in this manner contain only a very small amount of non-toxic impurities, are light in color and do not smell very slightly or in the absence of hydrogen sulphide. Likewise, hydrogen sulfide is not released from the reaction mixture during the reaction.

Reaction mechanism of alkylene bisdithiocarbamic acids, reap. their salts are not yet fully known. Zavizion and co-workers present the following reaction mechanism in the preparation of the 1,2-ethanebisdithiocarbamic acid diammonium salt:

cs.

^{EN 2/11} / ₊ . ^KH 3

NHG. / CHG / J. NHg-> NHg / XHg / gNHCSSM-> NH-j / CHg / gNHCSS-> NHg / CHg / gNHCSSM ^ / 1 /

CS,

NH,

-> HSSCNH / CHG / glíHCSSNH ^ -> _NH4 SSCN / CH _2/2 NHCSSNH _4/11 /

A similar procedure explains the formation of ammonium 1,2-ethanebisdithiocarbamidate Holan and Hinde (Australian Patent No. 237,152). In accordance with the above reaction scheme, it can be assumed that in the neutral environment the second amino group of 1,2-ethanediamine (ethylenediamine) does not react with carbon disulfide (JakuboviS A. Ja. - Klíma VA: W. Obšč. Chim. 1939, 9, p. 777) ). Thorn and Ludvig (The Dithiocarbamide and Relatide Compounds. Amsterdam-New York, 1962) report that the beta-aminoethylenedithiocarbamic acid (I) intermediate under these conditions forms an ethylenediamine inner salt of this type (III):

ch ₂ nhcssnh ₃ ch ₂ (III) - +

CH ₂ NHCSSNH ₃ CH ₂ Depending on the reaction conditions, some other reactions may also take place in the system of interest in addition to the desired reaction. For example, ammonium hydroxide pSsobením carbon disulfide to give a red solution, from which as mentioned scientific literature, may be isolated and orange žl'té kryítálky thiocarbonates - / NH _4/2 E _3, and / fffl _4/2 E ₄ (Cotton, FA - Wilkinson, G .: Inorganic Chemistry, Prague, Academia 1973, p. 316). Thiocarbonates in basic environments are according to Wertheim, Gattow and Hahnkamm (J. Am. Chem. Soc. 1926, 48, p. 826; Z. anorg. Allgem. Chem. 1969, 364, p. 161; ibid. 1969, 365, 70) decompose into sulphides and rodanides.

'Thiocarbonates are also decomposed by the action of air oxygen, which can be schematically represented as follows:

Na ₂ CS ₃ -> Na ₂ S + CS ₂

Na ₂ S + H ₂ O-> NaSH + NaOH

2NaSH + O-> Na ₂ S ₂ + HgO

Na ₂ N ₂ + 30-> Na ₂ N ₂ 0 ₃

The formation of carbonate is supported by the temperature and the action of the free alkali (even in the case of local re-alkalization).

Compound (I) can be a source of a variety of by-products. For example, Zavizion et al. (Chim. Prom. 1972, 3, p. 74-75) as well as Scroeder (Chem. Rev. 1955, 55, p. 81) report that its decomposition product is ethylene thiourea (ETU), and hydrogen sulfide:

NH ₃ (CH ₂ ) ₂ NHCSS> H ₂ S + ch ₂ CH

ETU

Oxidation of the ETU can then result in 2-imidazolidonethylene urea, 2-imidazoline (4,5-dihydroimidazole):

CH.

HN NH

_G CH ₂ CH

N ^x NH ₂ -CH ₂

2-imidazolidone

2-imidazoline (Marshal, WD - Singh, J .: J. Agric. Food Chem. 1977, 25, 1316-13320; Newsome, WH: Ethylenebisdithiocarbamates and Their Degradation Products. Analytical Methods for Pesticides and Plant Growth Regulators, Vol. XI, Academic Press, Inc., 1980, p, 97).

Also, alkylene bis-dithiocarbamidates themselves are relatively unstable (Thorn, G. D. - Ludwig, R, A .: Can. J. Chem. 1954, 32, pp. 872-879; Ludwig, R. A. - Thorn G. D. - Unwin,

C. H .: Can. J. Bot. 1955, 33 p. 42 to 59; Czegledi-Janko, G., J. Chromatogr. 1967, 3 ', p. 89 to 95). Zavizion and co-workers (Chim. Prom. 1972, 3,, pp. 174-175) report that the following products may be formed when oxidizing the 1,2-ethanebisdithiocarbamic acid dibasic salt:

CHjNHCSS CHjNHCS · ->

CHgNHCSS CH ₂ NHCS ·

S + Sqh ₂ nhCH ₂ NH

= S + CS1,2-ethanbistiuram disulfide (ethylenebistiuram disulfide), 2-ethantiuram · monosulfide (ethylenururammonosulfide)

If aqueous alkali metal dithiocarbamides are treated with an oxidizing agent 1, e.g. Clg, Jg, S-, Og, / Fe / CN / g / ^- or HgOg, the thiuram disulfides are obtained (Cotton. FA - Wilkinson G .: Inorganic Chemistry, Prague, Academia 1973):

R, NCS; + J -> R - N - C - S - S - C - NR, + 2 J *

2 2 l | || ² ss

The thiuram disulfides provide free radicals by heating, which may act as an inhibitor of further reactions.

As can be seen, in order to limit the formation of by-products in the preparation of alkene-bis-dithiocarbamic acid salts, it is necessary, while maintaining the optimum ratios between the reacting components and the optimum temperature ratios, to maintain them! also optimally the pH ratios of the reaction mixture, it is important to exclude the possibility of even short-term resp. locally achieving extreme pH values in the reaction mixture.

In this regard, it should also be noted that, for example, during the preparation of a 20% aqueous solution of 1,2-ethanebisdithiocarbamic acid bivalent ammonium salt according to the procedure of Tlen Flenner (U.S. Pat. No. 2,609,389) and Zavizina (Chim. Prom. 1972, 3i s). 174-175), monitoring the pH of the reaction mixture revealed that during the study reaction the pH of the undiluted reaction mixture reached various values ranging from 3.9 to 10.4.

Similarly only after several attempts repeated and only with the special attention of the experimenter, the pH changes of the reaction mixture were kept within the prescribed limits even during reproduction by controlled dosing of the reactants! the procedure proposed by Gobello. for the preparation of crystalline sodium 1,2-ethanebisdithiocarbamidate hexahydrate (U.S. Patent No. 2,693,485 - Example No. 4).

Practically all of the manufacturing methods and patents referred to in the literature refer only to batch-led production processes. The exception is the continuous process for producing dithiocarbamates protected by the NSR Pat. no. 11,186,186 and US Pat. no. No. 3,210,409, based on the reaction of carbon disulphide in a vapor phase (at a temperature above / above the boiling point of CS ₂ ) with a solution of one or more amines, at atmospheric pressure or a slightly elevated pressure (0.1 to

0.6 MPa), in a packing column.

This makes it possible to shorten the reaction time considerably, but its use in practice implies the construction of a special and relatively large-volume machinery, while the method of production only partially excludes the possibility of achieving extreme pH values in the reaction mixture.

It has now been found that most of the deficiencies of the already described methods can be overcome by preparing solutions of alk, ylene-bis-dithiocarbamic acid salts by reaction of carbon disulphide, C 2 -C 6 alkanediamines and ammonia and / or alkali metal hydroxide and / or metal hydroxide soil at a temperature of 20 to 60 ° C at a pH of 7.5 to 13.0 according to the invention.

The invention is based on the fact that alkanediamine, carbon disulphide and / or mixtures thereof and ammonia and / or alkali metal hydroxide and / or alkaline earth metal hydroxide are continuously fed into a circulating reaction medium consisting of a mixture of product, intermediates and reactants, the mass flow rate The reaction product may optionally be stabilized by addition of formaldehyde and / or paraformaldehyde and / or hexamethylene etramine.

A solution of alkylene-bis-dithiocarbamic acid salts can be prepared on the apparatus according to the invention, which consists of a reaction mixture tank which is connected via a pipeline to the circulation pump and optionally incorporated in the pipeline route between the tank and the circulation pump. a static mixer and / or heat exchanger, and also an alkanediamine feed, carbon disulfide feed, ammonia feed and / or alkali metal hydroxide and / or alkaline earth metal hydroxide feed, and the reaction tank is equipped with a continuously operating off-feed of the reaction product. The supply of alkanediamine and the supply of carbon disulphide may be common.

Said method makes it possible to adjust and maintain the pH of the reaction mixture practically completely constant during the continuous preparation of the alkylene bis-dithiocarbamic acid salt solutions and also to eliminate the possibility of the formation of concentration gradients in the reaction system.

The process of the present invention effectively avoids the possibility of local overheating of the reaction mixture due to the considerable exothermic reactions occurring in the system of interest and allows the reaction mixture to be maintained at the desired product-optimal temperature.

It has also been found that the pH of the reaction mixture which can be maintained during the continuous preparation of the alkylanbisdithiocarbamidate solutions by dosing the reactants is dependent on the type of hydrocarbon chain of the alkylenebisdithiocarbamidan to be prepared, the type of alkali, respectively. the nature of the salt to be prepared, the nature of the reaction medium and also the concentration of the reaction product solution to be prepared.

The optimum pH of the reaction mixture maintained during the continuous preparation according to the invention is close to the pH of the alkylene-bis-dithiocarbamidan solution of the appropriate type and the concentration with its theoretical stoichiometric ratio of all its atomic components.

In order to inhibit the formation of reaction by-products, it has been found expedient to work with up to a 6% excess of carbon disulphide and a 0.5 to 1.5% excess of ammonia and / or alkali metal hydroxide and / or 1.0 to 3, 0% excess of alkaline earth metal hydroxide relative to their stoichiometric amount. The addition of the corresponding alkanediamine in its diluted form, for example in the case of 1,2-ethanediamine in the form of a 30 to 70% aqueous solution, has also proved to be useful.

It has also been found that, in accordance with the statements of Hollan and Hinde (Australian Pat. No. 237,152), Flenner (US Pat. No. 2,609 3-9) and Zavizin and Associates (Chim. Prom. 1972, 3, pp. 174 to 175) it is preferable to mix the carbon disulfide and the alkanediamine under certain conditions for their addition to the circulating reaction medium, as a result of which it is expected that the reaction of these components will yield the corresponding beta-aminoalkyldithiocarbamic acid as an intermediate.

Two of the possible modifications of the device according to the invention are shown in the attached drawings. In FIG. 1 is a schematic illustration of a device according to the invention with a separate feed of the individual reactants into a pipeline route connecting the reaction vessel to the suction side of the circulation pump.

A schematic diagram of the process equipment with a common supply of carbon disulphide and alkanediamine to the pipeline on the suction side of the circulation pump and the supply of alkali to the pipeline on the discharge side of the circulation pump is shown in FIG. Second

The apparatus consists of a storage tank (J), a reaction mixture, a circulation pump (6) for circulating the reaction mixture, optionally a static clarifier (2), a heat exchanger (2) for tempering the reaction mixture, an alkanediamine inlet (2), carbon disulphide (6), ammonia and / or alkali metal hydroxide. alkaline earth metal hydroxide and drainage § for draining off the crude product.

In the process according to the invention, the reaction mixture is circulated from the reservoir and the reaction mixture by means of a circulation pump 2 through a static mixer 2 and the heat exchanger 2 back to the reservoir J.

The appropriate alkanediamine (1,2-ethanediamine, 1,3-propanediamine) is fed in the required amount to the suction line and into the discharge line of the circulation pump 2 through the inlet 2.

1,4-butanediamine, 1,5-pentanedlamine, 1,6-hexanediamine), carbon disulfide feed and feed 2 feed ammonia and / or ammonia water and / or alkali metal hydroxide solution and / or solution and / or an alkaline earth metal hydroxide suspension. A centrifugal pump is preferably used for circulation, in which a high degree of homogenization is achieved.

Carbon disulfide and alkanediamine have proven advantageous to be supplied to the suction line and to ammonia and ammonia, respectively. supply the appropriate hydroxide to the discharge part of the circulation pipe. as regards the order of dosing, it has proven expedient to dispense the carbon disulfide first, from the circulation pump by a distal inlet located on the suction side of the circulation pipe; feed the alkanediamine through the inlet located in front of the pump at the suction side of the pipe and ammonia, respectively. the respective hydroxide is metered in via the inlet built into the discharge part of the duct circulation path, preferably between the circulation pump and the static mixer or through the inlet built between the alkane diamine inlet and the circulation pump on the suction side.

This reagent can also be dispensed into the reservoir of the reaction mixture.

The crude product is continuously discharged by draining the product 8 through a liquid seal, or more preferably through a stirred intermediate tank, film evaporator and cooler to the product storage container. Swelling of the reactant components can be achieved by incorporating a suitable static mixer 2 into the circulation path of the reaction mixture, preferably into its discharge portion.

The dissipation of the released heat can advantageously be effected by circulating the reaction mixture through a suitable solution heat exchanger 2 of the reaction mixture, which is expediently incorporated into the discharge part of the circulation pipe.

The functional volume of the reservoir and the reaction mixture, including the volume of the circulation path and the dosing of the reactants, should be chosen so that the mean residence time of the reaction mixture in the apparatus is not less than 30 rains and no longer than 180 ml. The ratio of the weight flow rate of the circulating reaction mixture to the weight rate of carbon disulfide dosing is preferably maintained in the range of 350 to 750.

Removal of the unreacted carbon disulfide residue from the crude reaction product, especially when working with a larger excess of the stoichiometric need, has proven suitable to be treated by flowing the crude product through a continuously working, preferably film evaporator (e.g., helical type), tempered at 55 to 55 60 ° C. The carbon disulphide thus obtained after its condensation can be collected in a stock of raw material.

For the removal of unreacted carbon disulfide residues, a continuously operating separator can also be used and thus utilized to separate the CS ₂ from the crude reaction product by its limited miscibility with aqueous solutions of alkylene bis dithiocarbamates and their considerable different density.

23772 '

In order to eliminate the possibility of oxidation of the intermediates and the product with air oxygen and thereby inhibit the formation of some undesirable by-products (such as: alkylbistiuram disulfide, alkylthiurammonosulfide θ similar), it is advisable to keep the reaction mixture reservoir as well as other devices in which the reaction mixture is in contact. a product with air oxygen, a protective layer of inert gas (eg nitrogen, argon, carbon dioxide and the like).

The continuous process for the preparation of the alkylene bis dithiocarbamate solutions according to the invention furthermore also excludes the influence of the atmospheric atmosphere even in the absence of a protective inert atmosphere.

In case the reaction product-alkylene bis-dithiocarbamate solution is not readily processed, it is suitable to stabilize it by adding hexamethylenetetramine or methanol and / or to maintain a protective layer of inert gas or a non-immiscible and inert liquid layer in the product storage container.

The examples given below illustrate but do not limit the scope of the invention.

Example 1

In order to study the continuous process of preparing solutions of salts of alkylenebisdithiocarbamic acids and apfisob according to the invention, a laboratory apparatus has been constructed, which is schematically shown in FIG. Third

The apparatus consisted of two modified and interconnected 2,000 and 1,000 cm < 3 > A vial (V = 2,000 cn?) Was connected through a special all-glass segment for the midrange outlet at the bottom of the vessel into which three conically tapered feeds of the dosed reactants to the suction side of the centrifugal rotary pump made of PTFE resulted.

The discharge side of the pump was connected via a thermometer vial (t ^) and a duplicated glass tube with punctures fulfilling the function of a static mixer, to a glass connector leading to a 2,000 cm ^ flask. In this way, a circulating circuit of the reaction mixture was formed into which the feeds of the reactants flowed into the suction side.

The volume of the retainer, the size of which was determined by the pre-indentation of the overflow on the perimeter of the flask, was equal to 1800 cm. The overflow of the 2,000-cm flask was designed to form a liquid closure and into a second 1000-liter brewing flask located below. This flask was equipped with a stirrer and similar to the previous one had a bottom outlet at the bottom ending with a liquid closure.

The liquid retained in this flask was 636 cm < 3 > Below the surface of the larger flask forming part of the circulating circuit, a glass mercury thermometer (i.e.) and reference (saturated calomel, Er) as well as indicator (glass, high ohm, E ^ j) electrode. The electrodes used for continuous monitoring of changes in pH of the reaction medium were connected to the pH-meter of OP-207 type from Radelkis.

By means of repeated measurements with water, the mean volumetric flow rate through the circulating circuit (Vjj θ = 25.65 cm @ ^-1 s ^-1 ) was determined.

In this experiment, the continuous preparation of an aqueous solution of 1,2-ethene-bis-di-thiocarbamic acid, a bivalent ammonium salt according to the invention was verified.

The aqueous ammonium 1,2-ethanebisdithiocarbamidate solution required to flood the previously described continuous operating apparatus was prepared in a batch process according to Flenner (U.S. Pat. No. 2,609,389).

Chemically purified (Pitra J. et al .: Laboratory Treatment of Chemicals and Auxiliaries, Prague, SNTL 1969) was used during the preparation of the product needed to overwhelm the apparatus, as well as during its own continuously conducted process for preparing an aqueous solution of 1,2-ethanebisdithiocarbamic acid bivalent ammonium salt. pp. 80 to 81;

Introduction to preparative inorganic chemistry. Prague, SNTL 1972, p. 283) and distilled carbon disulphide, the purity of which was controlled by boiling at atmospheric pressure and determining the refractive index by means of an Abbe refractometer at 20 ° C (n ° = 1.677).

The technical 1,2-ethanediamine used was purified by reactivation at atmospheric pressure (t = 116.5 ° C). the purity of the distillate was controlled by boiling point and refraction to 20 x metric (measured refractive index n = = 1.4555 δ). The ammonia water used in this experiment was declared pure and was titrated to contain 21.3% NH ₃ :

During the discontinuous preparation of 1,2-ethanebisdithiocarbamide acid, a bivalent ammonium salt according to the procedure of Flenner, the following components were used:

distilled water 38.66 wt. % carbon disulphide 25.85 wt. % 1,2-ethanediamine 9.62 wt. % ammonia water (21.3% NH ^) 25.87 wt. %

The isotachophoretic assay determined a 36.05% content of active ingredient in a sample of the prepared product.

During their own continuous experiment, the peristaltic metering pumps were dosed into the circulating product containment at an average volumetric rate of:

47.7. 10 ~ ³ cm ^{3 EN} ₂ . s ^- '

50.5. Cm ³ cm ^{3 of} an aqueous 44.6% solution, 1,2-ethanediamine. s ^- '

131.05. ΙΟ- ^{3 cm3} of dilute ammonia water (10.5% N H) .s ^_1.

The amounts of reactants actually fed were determined from the weight changes of the respective stock scales placed on the scales. In this way, it was found that the actual average mass flow rate of the dosed reagents during the experiment was as follows:

60.10. 10 ³ g EN ₂ . s ^_1

50.25. 10 ~ ³ g of 1,2-ethanediamine (44.6%). s ^-1 133.21. ! 0 ~ ³ g of ammonia water (10.5% NH?). s ~ ¹ .

In order to temper the reaction mixture to the desired temperature (40 ° C), water of the indicated temperature was circulated in the static mixer jacket (length: 800 mm) from the thermostat.

At an average circulating water temperature in the thermostate of 40.25 ° C, the average temperature of the reaction mixture downstream of the centrifugal pump was 39.6 ° C and the average temperature in the reservoir! - about

- the brewing bank was 40.5 C. Ha unlike the commonly used discontinuous methods of preparation, which were verified in the past period (AO No. 197 196, Flenner - Zavizion Process, Gobell's preparation procedure), in which the extent of changes The pH of the reaction mixture usually corresponds to five to six pH units, during the continuous experiment discussed, the pH of the reaction mixture was practically constant and at least fluctuated around an average of 8.4.

the time courses of pH changes of the reaction mixture during the preparation of 1,2-ethanebisdithiocarbamic acid sodium and ammonium salts by the most well known methods known in the patent and literature and in a continuous manner according to the invention are shown for comparable periods of time in FIG. 4th

In the upper part of FIG. 4 shows the time course of changes in pH of the reaction mixture in the preparation of 1,2-ethanebi-dithiocarbamic acid disodium salt according to Gobell (U.S. Pat.

no. 2,693,485 - reproduction of the preparation method according to example no. 4).

In the middle of the figure, the time dependence of the pH of the reaction mixture during the preparation of the 1,2-ethanebisdithiocarbamic acid dibasic salt according to the method of Flenner (U.S. Pat.

no. 2,609,389) and Zavizion et al. (Chim. Prom. 1972, 3,5, 1974-1975).

The last third dependence shown in FIG. 4 is a portion of the pH recording of the reaction mixture obtained by the panning pH meter meter. Radelkis (type OP-207) during the continuous preparation of about 35 16-aqueous ammonium 1,2-ethanebisdithiocarbamldane solution according to the invention (Example 1).

During several hours of continuous operation of the apparatus under test, a pale yellow solution of ammonium 1,2-ethanebisdithiocarbamamiden was obtained, which smelled very slightly of hydrogen sulfide. By averaging the results of eight chemical analyzes during the sampling, it was found that it contained an average of:

35.30 wt. Ammonium 1,2-ethanebisdithiocarbamidate (determined by precipitation titration with Pb-salt solution with potentiometric indication of equivalent point), respectively.

34.46 16 wt. Ammonium 1,2-ethanebisdithiocarbamidate (determined by averaging the results of isotachographic assays).

A moderate Abbe refractometer measurement for 8 product samples taken at 20 ° C was: n ² ° = 1.469 8.

The chromatographic analysis of the samples was carried out by TCL using commercially available Lucefol-ftuick cellulose chromatography layers, 20 x 20 cm. For the aluation system was used: n - propanol - water. At start, a 10 μΐ solution containing 0.35 g of a sample of an aqueous solution of ammonium 1,2-ethanebisdithiocarbamate in 10 cm roztoku of the stock solution was applied by microdosing. The ferrocyanide-nitroprusside reagent was used for detection.

Isotachophoretic analysis of samples of the solutions of the barium ammonium salt of ethylenebisdithiocarbamic acid obtained during the described continuously conducted experiment was performed under these conditions.

Hydrochloric acid in a mixture with beta-alaine (pH solution 4, Oj chloride concentration c = 0.01 M) was used as the lead electrolyte. A 0.01 M glutamic acid solution was used as the ending electrolyte. Separation was performed at a current intensity of 200 μΑ in a 0.3 mm column and approx. 18 cm in length. The column was made of organic glass and PTFE (Teflon).

1

A gradient potential detector was used for zone detection. For analysis, 2 µl of a stock solution of cce concentration of 0.0 µl was injected. M of the test substance. The assay result was quantitatively evaluated by the calibration curve method. The isotachograms (time courses of variation of resistance in zones during separation) of two of the dsray samples taken in FIG. 5. The individual parts of the isotachograms of the two samples (Fig. 5) correspond to the separation of the lead electrolyte chloride (O), ethylene bisdithiocarbamidan (2) and the electrolyte-glutamate (3).

The two separation methods used confirmed the high purity of the product prepared in the course of a continuously run laboratory experiment according to the invention.

Example 2

During this continuous experiment, the preparation of an aqueous solution of 1,2-ethanebisdithiocarbamic acid magnesium salt according to the invention was verified using a laboratory apparatus as specified in Example 2. 1. Pracovalo; with carbon disulphide and 1,2-ethanediamine of similar purity to the previous example.

Magnesium hydroxide, prepared by precipitation of an aqueous solution of MgSO 4 with dilute ammonia water, was used as the magnesium source. The Mg / OH / g precipitate was freed from (NH4) gSO4 by repeated decantation with distilled water. For a five hour continuous run, the required amount of magnesium hydroxide was prepared by precipitating 629 g of anhydrous MgSO 4 and MgSO 4, respectively. 1 288 g. MgSO. 7H ₂ 0. The device was dosed on average:

45.50. 10 * 3g. s ^- 'carbon disulphide, CS ₂ ;

33.87. 10 * 3g. _g -1 jo eh% _ _n d _{n 0 the} solution mixed, and 1,2-ethanediamine

254.12. 10 3 g, _S 1 β, γ% Mg / OH / ₂ suspension, spiked (similar to CS ₂ and

Η Ν ₂ / 0Η _2/2 ΝΗ ^ / peristaltic - hose pump from a stirred reservoir magnesium hydroxide. By circulating water through the static mixer jacket downstream of the centrifugal pump, the temperature of the reaction mixture was maintained at 39-42 ° C. The pH of the circulating reaction mixture varied between 8.7 and 9.3 during the experiment.

Under the above conditions, about 1,200 g of crude reaction product were obtained per hour, from which the unreacted carbon disulfide residue was stripped off by briefly heating it to 55-57 ° C. The reaction product thus prepared was a clear solution of a slightly yellowish color, which only faintly smelled of hydrogen sulfide. Titration of the lead salt solution with potentiometric indication of the equivalence point indicated that the averaged product from the nearly five-hour, continuously run experiment contained 21.08% by weight. Magnesium 1,2-ethanebisdithiocarbamidate.

Example 3

In the preparation of an approximately 30% aqueous solution of 1,2-ethanebisdithiocarbamic acid disodium salt according to the invention, the laboratory apparatus described in Example 1 was used. The carbon disulfide and 1,2-ethanediamine used were treated in a similar manner to the previous two. attempts. On average, the following were dosed into the circulation circuit by means of half-feed inlets before the circulation centrifugal pump:

93.54. 10 * 3g. s ~ ¹ carbon disulphide;

87.0. 10 * 3g. _g -1 of a 40% aqueous solution of 1,2-ethanediamine a

319.46. 10 * 3g. _with 14.65% aqueous NaOH.

The temperature of the circulating reaction mixture was maintained at 39.6 to 40.3 ° C. The continuous recording of the pH of the reaction mixture showed that the pH of the reaction mixture was in the range of 9.4 to 10.2 during more than 4 hours dosing of the reactants.

Assuming that the average volumetric water flow through the circulation circuit was 25.65 cm ^-3 . s ^-1 and assuming a constant value of the specific gravity of the reaction mixture (ú ^ qOq = 1 160 kg.m ^-3 ) it can be stated that the ratio of the volumetric flow rate of the circulating reaction mixture to the volumetric dosing rates of the reactants was 59.5 and similar weight the ratio was 51.3 during this experiment.

Under the above conditions, about 1,600 g of crude reaction product were obtained on average per hour. The residual unreacted carbon disulfide was removed from the crude reaction product by heating to 56 ° C.

Chemical analysis of the product obtained indicated that it contained 98.40 moles of active ingredient per 100 g of sample, corresponding to 25.2% of 1,2-ethene-bis-ditlokarbamic acid disodium salt.

The specific gravity of the reaction product for which the? 20 value of 20 ° C ⁼ 1.68.5 kg was determined by measurement. m, _and its refractive index n = 1.445 was also determined.

Example 4

In this experiment, the use of the method of the invention was tested for the preparation of the crystalline disodium salt of 1,2-ethanebisdithiocarbamic acid, C ^ HHNNgS NagN Nag · 6H HO. The continuous apparatus was run on the laboratory apparatus specified in Example 1 (schematically shown in Figure 3).

In order to obtain the greatest possible yield of the crystalline salt, relatively concentrated reactants were used in the preparation thereof, as described above, with the chemically purified and distilled carbon disulphide described above, a 40.5% solution of 1,2-ethanedlamine (prepared by flushing the distilled 1,2-). ethanediamine with distilled water) and an aqueous solution of about 50% NaOH.

On average, to the circulation circuit, just before the used pump with separate feeds, dosed:

95.14. 10 “ ³ g 87.47. 10 ^-3 g 95.17. 10 ^{-1 3} g of carbon disulfide, 40.5 ^s-1 s-solution water and 1,2-ethanediamine ^-1 50% aqueous NaOH.

It follows that the weight ratio of the rate of circulation of the reaction mixture to the rate of dosing of the components was 92.3. By circulating the reaction mixture through a water-tempered heat exchanger-static mixer, the temperature of the reaction mixture was maintained within the range of 38.6 to 41.2 ° C during 320 minutes of dosing of the reactants. The pH of the reaction mixture was maintained between 9.6 and 10.7 throughout the duration of the experiment.

The crude reaction product, flowing out of the 2,000 cm ³ flask forming the reaction vessel reservoir through the side overflow equipped with a liquid cap, was collected in a glass reservoir, which was placed in an aqueous tempering cabinet, which allowed rapid reaction after dosing. heating the crude product containment to 55 ° C to remove residual unreacted carbon disulphide, and also cooling it to about 30 ° C.

During this operation, a considerable amount of solid crystalline phase was eliminated. By filtration of the so-obtained crystalline suspension, 61.8 wt. % wet filter cake (of the total weight of the separated mixture). The filtrate was left at room temperature the next day, leaving an additional 7.6 wt. % wet filter cake (based on filtrate weight). Air analysis of the freely dried crystalline product from the first crystallization revealed that it contained:

95.75% of the active ingredient (considered as C CHgNjS ^ Naj NajH NajOg),

31.76% of total sulfur and 7.58% of total nitrogen.

The crystalline product from the second crystallization (separation of the precipitated solid crystalline phase from the filtrate after the first crystallization) contained:

97.62% of the active ingredient (considered as C C HHgNgS Nag Nag. 6ΗΗ 0 0),

7.80% of total nitrogen and

32.63% of total sulfur.

Titration of the filtrate after a second crystallization with a lead salt solution having an equivalent point potentiometric indication indicated that it still contained 39.71% of the active ingredient as a solution.

Purification of the obtained crystalline product by further crystallization thereof yielded a 99.8% crystalline disodium salt of 1,2-ethanebisdithiocarbamic acid, C C ^HgNgS ^N Nag.

. Which could be used as a standard in chromatographic and isotachophoretic analysis.

Claims (5)

OBJECT OF THE INVENTION 1. A process for preparing solutions of alkylene-bis-dithiocarbamic acid salts by reacting carbon disulphide, C 2 -C 6 alkanediamines and / or alkali metal hydroxide and / or alkaline earth metal hydroxide at a temperature of 20 to 60 ° C and a pH of 7.5 to 13.0, characterized in that the alkanediamine, carbon disulphide and / or mixture thereof and ammonia and / or alkali metal hydroxide and / or alkaline earth metal hydroxide are continuously fed into the circulating reaction medium consisting of a mixture of product, intermediates and reactants, wherein the weight flow rate of the circulating reaction mixture is 50 to 3000 times the weight rate of carbon disulfide dosing. 2. Method according to claim 1, characterized in that the reaction product is stabilized by addition of formaldehyde and / or paraformaldehyde and / or hexamethylenetetramine. 3. Apparatus for carrying out the method according to claim 1, characterized in that it comprises a reaction mixture tank (1) which is connected to a circulation pump via a pipeline. whereby a static mixer (3) and / or a heat exchanger (4) as well as an alkanediamine inlet (5), a carbon disulphide inlet (6) are incorporated in the pipeline route between the container (1) and the circulation pump (2), the feed (7) of ammonia and / or alkali metal hydroxide and / or alkaline earth metal hydroxide and the reaction mixture tank (1) is provided with a continuously working off (8) of the crude reaction product. 4. The apparatus of claim 3, wherein the alkanediamine feed (5) and the carbon disulfide feed (6) are common.