Method for production of biuret with usage carbamide as the source product and the device for the method realization

FIELD: chemical industry; methods and the devices for production of the biuret.

SUBSTANCE: the invention is pertaining to the method of production of biuret and to the device for its realization. The process includes production in the pyrolysis furnace of the biuret and ammonia by the carbamide pyrolysis, purification of the gained biuret in the reactor of the recrystallization, production of the salt of the monohalogenbiuret metal by interaction of the biuret with the compound of the hypohalogen metal or with halogen and the base in the first reactor. Interaction in the second reactor of the produced biuret metal salt with ammonia, including the ammonia produced during the pyrolysis process of carbamide at the molar ratio of the salt of the monohalogenbiuret metal and the total amount of the ammonia making 1:1-1:1000. The separated excess of the ammonia extracted from biuret in the ammonia evaporator is sent to the ammonia concentrator. At that the ammonia concentrator is intended for concentration of the excess of the ammonia and the ammonia produced in the pyrolysis furnace and for delivery of the concentrated ammonia in the second reactor. The technical result of the invention is the development of the economically profitable continuous process with high efficiency and utilization of the easily accessible source product, reduction of the quantity of the by-products.

EFFECT: the invention ensures the development of the economically profitable continuous process with high efficiency and utilization of the easily accessible source product, reduction of the quantity of the by-products.

14 cl, 62 ex, 12 tbl

 

The technical field to which the invention relates.

The present invention relates to a method and apparatus for obtaining hydrazodicarbonamide of urea as the source of the product, more preferably to an advantageous from an economic and ecological point of view, a method and apparatus for obtaining hydrazodicarbonamide, including obtaining biureta of urea and interaction obtained biureta with the ammonia formed during the synthesis biureta.

The level of technology

Hydrazodicarbonamide (HDCA) is a compound suitable for use as a raw product to obtain azodicarbonamide, which is widely used as a foaming agent. As shown in reaction equation 1, azodicarbonamide (2) can be obtained by oxidation of hydrazodicarbonamide (1) the appropriate oxidation agent.

[equation 1]

Traditional ways of getting hydrazodicarbonamide include methods, which are based on (i) the use of hydrazine as the original product, (H) direct synthesis of urea, (iii) receive semicarbazide of urea and subsequent conversion of the obtained semicarbazide in hydrazodicarbonamide and (iv) application biureta as the original product.

The way in which use hydrazine in kacestvennogo product (equation 2), hydrazodicarbonamide produced by interaction of one mole of hydrazine (3) with two moles of urea (4).

[equation 2]

The above reaction has the advantage that the process is simple, but at the same time it has its drawbacks, namely that the hydrazine used as starting product is synthesized with difficulty and is an expensive product. Typical methods for producing hydrazine include the process on the Process and the method of obtaining from Katsina. However, there are some problems, namely that the hydrazine obtained by these methods requires stages of concentration and hydrolysis, and therefore energy costs and equipment costs are too high, and, accordingly, the cost of production increases. Moreover, hydrazine can also be obtained from the urea in the interaction of urea with sodium hypochlorite and sodium hydroxide. But this method requires an excess of sodium hydroxide and entails very high costs associated with the removal of sodium carbonate as a by-product, this requires a large number of chemical reagents to remove the specified by-product. Thus, this method is seen as undesirable from an economic and environmental point of view.

the alignment of the reaction of 3 illustrates a method for direct synthesis of hydrazodicarbonamide of urea. As shown in equation 3, three mole of urea interacting with each mol of sodium hydroxide and one mole of chlorine, you get one mole of hydrazodicarbonamide. But this method is also unsuitable, because of the need to use excessive amounts of reagents its cost is high and, in addition, the process is very complicated. There is another important problem, namely, that produce large quantities of ammonia as a by-product, which is environmentally undesirable.

[equation 3]

Equation 4 illustrates another method of synthesis of hydrazodicarbonamide. This method includes the stage of receiving semicarbazide of urea and subsequent transformations of the obtained semicarbazide in hydrazodicarbonamide. As shown in the reaction equation 4, the sodium salt of monochloracetic produced by the interaction of urea with sodium hypochlorite, and then sodium salt of monochloracetic subjected to interaction with an excess of ammonia in the presence of a catalyst to obtain an intermediate compound (semicarbazide), and then the formation reacts with urea with the formation of the final product (hydrazodicarbonamide).

[equation 4]

However, this reaction is also economically disadvantageous because it requires more than 500-fold excess of ammonia on sodium salt of monochloracetic or formation obtained using an expensive catalyst. There is another problem, namely, that a full cycle of the process is extended, as should be additional reactions for the conversion of semicarbazide in hydrazodicarbonamide.

Equation 5 illustrates the synthesis of hydrazodicarbonamide of biureta (PCT/KR00/00180). The method includes a step for metal salt of monohalogenated interaction biureta with yogalayam metal (MOSS) and the stage subsequent interaction of the obtained metal salt of monohalogenated with ammonia to obtain hydrazodicarbonamide.

[equation 5]

However, the above method of producing hydrazodicarbonamide using as starting product biureta has disadvantages, namely, that in General, the process is uneconomical and environmentally undesirable, because biuret used as the source of the product is either very expensive, or contains a lot of impurities, and, in addition, the interaction biureta with ammonia in the synthesis of hydrazodicarbonamide you on the additional amount of ammonia.

Disclosure of inventions

The object of the present invention is a method of obtaining hydrazodicarbonamide, economically and environmentally, using as starting product of urea, which is cheap and readily available.

In addition, an object of the present invention is a method and apparatus for obtaining hydrazodicarbonamide, which can reduce the quantity of generated by-products and used the original connections.

The object of the present invention is a method and apparatus for obtaining hydrazodicarbonamide with high yield in the implementation of the whole process in a continuous mode.

To achieve these goals in accordance with the present invention, a method for obtaining hydrazodicarbonamide, which includes the following stages: receiving biureta formula 1 and ammonia by pyrolysis of urea; obtaining metal salt of monohalogenated formula 2 or 3 interaction obtained biureta with metal yogalayam or halogen and a base; the interaction of the obtained metal salt of monohalogenated with ammonia.

[formula 1]

[formula 2]

[formula 3]

In these you who e formulas 2 and 3, M is a metal, and X represents halogen. Preferably the temperature of the pyrolysis of urea is 100˜300°C, the pyrolysis is carried out until the termination of allocation of ammonia and excreted ammonia reacts with the metal salt of monohalogenated.

The present invention also relates to a device for receiving hydrazodicarbonamide, which includes a pyrolysis furnace to obtain biureta and ammonia by pyrolysis of urea; the reactor recrystallization purification biureta obtained in the pyrolysis furnace; a first reactor to obtain a metal salt of monohalogenated by interaction biureta connection metal hypogalactia or halogen and the base; a second reactor for the synthesis of hydrazodicarbonamide by reacting a metal salt of monohalogenated with ammonia; the ammonia evaporator for separating excess ammonia from hydrazodicarbonamide and direction of the selected ammonia in the ammonia hub.

Preferably, ammonium hub serves for the concentration of excess ammonia and ammonia, derived from a pyrolysis furnace, and also for delivery of concentrated ammonia in the second reactor. The pyrolysis furnace may include a gas injector for supplying an inert gas that does not interact with isocyanates acid in the pyrolysis furnace, and may include devices for reducing pressure is Oia, to remove the ammonia from the pyrolysis furnace.

Brief description of drawings

A more complete understanding of the invention and many of its related advantages will be easily visible from the subsequent detailed description in conjunction with the submitted drawing, which shows a schematic diagram illustrating a system of apparatus for receiving hydrazodicarbonamide, in accordance with an embodiment of the present invention.

The implementation of the invention

The present invention will become more understandable from the following detailed description with reference to the accompanying drawing.

To get hydrazodicarbonamide in accordance with the present invention, first through pyrolysis of urea at a temperature above the melting temperature of urea receive biuret represented by formula 1, and ammonia. As a rule, biuret widely used as a source connection for receiving pharmaceuticals, herbicides and reagents for analysis, it is also used in large quantities as food for ruminants, and are used in various fields associated with plastic resins. In addition, it is known that some derivatives biureta can be used as a physiological agent, wound healing, or chemical therapeutic agent. The following equation re the work 6 illustrates a method of synthesis biureta by pyrolysis of urea.

[equation 6]

Equation 6 shows that the pyrolysis of 2 moles of urea gives biuret when the removal of a molecule of ammonia. More strictly, as shown in equation 7, it is assumed that initially, during the pyrolysis of urea is formed solanova acid and ammonia, and then solanova acid reacts with another molecule of urea, which gives the target product - biuret.

[equation 7]

Synthesis biureta by pyrolysis of urea has the advantage that the reaction is simple and its implementation is easy, but also have some disadvantages, namely, that the rate of conversion of urea in biuret is low due to the availability of sufficient amounts of impurities, such triuret, cyanuric acid, which are formed in the interaction biureta with isocyanates acid in education biureta. With increasing temperature and increasing the reaction time, the conversion rate increases, but also increases the amount of impurities, such triuret and cyanuric acid. However, at lower temperatures in order to reduce the number of impurities, the reaction rate decreases dramatically, which makes the process uneconomical. According to the present invention to increase the output of biuret and reduce impurities, the reaction temperature is preferably maintained between 100˜300°and, more preferably, in the range of 130-170°C.

Moreover, if an inert gas, such as air and nitrogen, which do not react with isocyanates acid, is introduced into the reactor and/or the pressure in the reactor is reduced, ammonia, a byproduct formed during the reaction, can be effectively removed from the reactor, after which the reaction rate increases and the formation of impurities can be reduced. In addition, as the source of inert gas can be used for liquid-phase organic compound, which can replace the inert gas in the reactor with high temperature.

If necessary to increase the speed of pyrolysis can be applied to the catalyst. As the catalyst preferably can be used an inorganic acid catalyst, such as nitric acid, hydrochloric acid and sulfuric acid, and an acid type catalyst, such as thionyl chloride and phosphorus-containing compounds, such as sodium phosphate. The preferred amount of catalyst is 0.001˜0.5 mol per 1 mol of urea, and a more preferred amount is 0.01˜0.3 mol per 1 mol of urea.

Salt of the metal of monohalogenated formula 2 or formula 3 can be obtained by reacting the floor is built biureta connection metal hypogalactia or halogen and grounds.

[formula 2]

[formula 3]

In the above formulas 2 and 3, M represents a metal, and X represents halogen.

Direct method of obtaining a metal salt of monohalogenated by interaction biureta connection metal hypogalactia illustrated by equation 8. A concrete example illustrates equation 9.

[equation 8]

In the above equation, M represents a metal, and X represents halogen.

[equation 9]

In equation 9 biuret reacts with sodium hypochlorite with the formation of the sodium salt of Glorieta. Since the reaction is exothermic, the reaction system should preferably be maintained at a low temperature. But the resulting sodium salt of Glorieta is stable under moderate heating, it can be obtained at room temperature. The preferred reaction temperature should be less than 60°more preferred temperature is in the range of -10˜60°and the most preferred temperature is in the range of -5˜35°C. To ensure the greatest economic efficiency and operational capacity of the molar ratio of the metal hypohalide the and 1 mol of urea if the reaction is preferably from 0.1 to 2. When the molar ratio is less than 1 mol, excess biuret can be returned and reused. In the case where the molar ratio in the reaction is less than 0.1 or the reaction temperature is less than -10°C, the reaction time will increase. In that case, if the molar ratio in the reaction is greater than 2, the cost of the product increases and can go adverse reaction. If the reaction temperature is more than 60°obtained salt of a metal of monohalogenated can decompose because it is unstable at high temperature. The sodium salt of carburet obtained under the above conditions, may be used directly or may be stored for the next stage of the process.

A method of obtaining a metal salt of monohalogenated the above formula 2 or 3, by reacting biureta with halogen and base illustrated by equation 10. In accordance with equation 10 salt of the metal of monohalogenated can be obtained by adding a base such as a metal hydroxide (e.g. sodium hydroxide, potassium hydroxide, calcium hydroxide) to monohalogenated (5), obtained by interaction biureta with halogen, such as chlorine, or a derivative of halogen.

[equation 10]

In equation 10 M represents a metal, and X represents halogen.

Taking into account the fact that the reaction of obtaining monohalogenated (5) is exothermic, positive that the reaction temperature was maintained at a lower level, in particular below 60°C, preferably in the range of -10˜60°and most preferably in the range of-5-30°to ensure sufficient response speed and stability of it. Alternatively, a metal salt of monohalogenated can be obtained by mixing a metal hydroxide with bureta with subsequent interaction of the halogen with the received product. Due to the fact that this reaction is also exothermic, the reaction temperature should be maintained at a lower level, in particular in the range of -10˜60°s and more preferably in the range of-5-30°C. When conducting the specified reaction in the case when the reaction temperature falls below 10°With time the reaction should be much increased, and in that case, when the reaction temperature is above 60°S, salt of the metal of the can monohalogenated decompose because it is unstable when heated. As illustrated by equation 11, the obtained salt of a metal of monohalogenated may be the salt is of atalla 3-monohalogenated (6) or salt of the metal 1 monohalogenated (7).

[equation 11]

To get hydrazodicarbonamide formed salt of the metal of monohalogenated subjected to interaction with ammonia, which is released during the pyrolysis of urea. The reaction mechanism is assumed to be similar to the reaction mechanism on Favorsky, illustrated by equation 12, or rearrangement reaction by Hoffman, illustrated by equation 13.

[equation 12]

[equation 13]

In the above equation 12 due to intermolecular reactions of anionic nitrogen atoms in the metal salt of monohalogenated (8) during the formation of the nitrogen-nitrogen relation is obtained unstable derived diaziridine (9), and the connection of halogenmethyl cleaved. Derived diaziridine (9) readily reacts with reactive ammonia with the formation of hydrazodicarbonamide. In addition, according to the above equation 13, it is assumed that the salt of the metal of monohalogenated transformed into a compound that contains an isocyanate group, and formed isocyanate compound interacts with reactive ammonia with the formation of hydrazodicarbonamide.

For the reaction of the metal salt of monohalogenated with ammonia, which is a side PR is the product of the pyrolysis of urea, with optimal speed and efficiency, the preferred reaction temperature is the temperature, in the interval between 0 and 150°C, more preferably between 30 and 150°C. When the reaction temperature falls below 0°C, the reaction rate slows down, and the reaction becomes economically inefficient. In the case when the reaction temperature rises above 150°increases the cost of the equipment, because it must be designed to withstand the internal pressure caused by the evaporation of ammonia.

Ammonia can be used both in gaseous and in liquid form or in the form of ammonium hydrate. To increase the reaction rate, it is preferable to use ammonia in excess. The amount of ammonia can be between 1 and 1000 mol per 1 mol of metal salt of monohalogenated, more preferably between 2 and 500 mol, most preferably between 5 and 100 mol. The excess of ammonia, with the exception of 1 mole of ammonia which reacts with 1 mol of metal salt of monohalogenated, can be separated and reused in the next cycle of the process. When the reaction temperature is high, in the case when using large amounts of ammonia, the pressure in the reaction system can be raised to prevent the evaporation of ammonia. This mode allows you to increase the reaction rate and its efficiency, thus the preferred range of pressure is between 1 and 100 kgf/cm2.

In accordance with the present invention, a high output can be achieved without the use of a catalyst. However, the use of a catalyst is very useful, because it allows to reduce the time of the reaction and to increase its efficiency. Examples of catalysts include at least one compound selected from the group consisting of sulfates, chlorides, carbonates or hydroxides of the base metal or amphoteric metal and ORGANOMETALLIC compounds. The preferred amount of catalyst is in the range between 0.001 and 1 mol, more preferably in the range of 0.01˜0.5 moles per 1 mole of the metal salt of monohalogenated. Inorganic acid, such as sulfuric acid, hydrochloric acid or nitric acid, as the catalyst may be added in quantities of 0.05˜3.0 mol per 1 mol of metal salt of monohalogenated.

The solvent reagent (biureta) or internal reaction medium can be used water. If necessary, as the second solvent may be added, at least one solvent selected from the group consisting of a polar solvent, such as methanol, ethanol, propanol, isopropanol, tetrahydrofuran, acetonitrile is aprotic solvent, such as dimethylformamide, dimethylsulfoxide, dimethylacetamide. The amount of the second solvent is not particularly limited, but the preferred amount is from 0.1 to 50-fold relative to the total weight of water, more preferred amount is 0.2 to 3.0. The second solvent may be introduced at the beginning of the reaction, as a solvent for biureta, or after mixing the solution biureta with sodium hypochlorite solution.

The reaction of obtaining hydrazodicarbonamide of urea as the source of the product in accordance with the present invention entirely illustrated by equation 14. Device for receiving hydrazodicarbonamide in accordance with an embodiment of the present invention shown in the drawing.

[equation 14]

As shown in the drawing, the apparatus for receiving hydrazodicarbonamide in accordance with an embodiment of the present invention includes a pyrolysis furnace 10 to obtain biureta and ammonia gas by pyrolysis of urea. Pyrolysis furnace 10 preferably includes a gas injector 12 for supplying inert gas into the pyrolysis furnace 10 or may include devices (not shown) for reducing the pressure in the furnace 10, to easily remove the ammonia from the pyrolysis furnace 10. Examples of inert gas include, but are not limited to such, air, nitrogen is liquid-phase organic compound, which replaces the inert gas in the pyrolysis furnace 10, because it does not interact with isocyanates acid.

Ammonia is removed from the pyrolysis furnace 10, preferably served in ammonia hub 20, the function of which is the concentration of ammonia supplied from the pyrolysis furnace 10, and the excess amount of ammonia remaining after the formation of hydrazodicarbonamide. Impurities such as cyanuric acid and triuret present in biurate obtained in the pyrolysis furnace 10, separate devices for recrystallization, which include the reactor recrystallization 30 and dehydrator 32, such as a centrifuge, and then fed to the first reactor 40.

Purified biuret, which is fed to the first reactor 40, is reacted with a compound of the metal of hypogalactia (e.g., NaOCl) or halogen (e.g. chlorine) and the substrate with the formation of the metal salt of monohalogenated, and then the metal salt of monohalogenated served in the second reactor 50. Salt of the metal of monohalogenated subjected to interaction with ammonia to obtain hydrazodicarbonamide, ammonia, however, is preferably supplied from the ammonia hub 20. The resulting hydrazodicarbonamide and the excess ammonia is served in the ammonia evaporator 52. Ammonia evaporator 52 vaporizes the excess ammonia, and evaporated ammonia is served in the ammonia concentrate the R 20. Hydrazodicarbonamide separated from the excess of ammonia, cleaned using dehydrator 54, such as a filter.

As shown in equation 13 and in the drawing, hydrazodicarbonamide in accordance with the present invention can be obtained in one continuous process of urea used as starting product. Since the entire process is carried out continuously, its efficiency can be improved. In addition, the product cost can be significantly reduced due to a significant reduction in the number of raw materials due to the fact that the salt of the metal of monohalogenated reacts with ammonia, which is obtained as a by-product in the process of education biureta. Thus, hydrazodicarbonamide can be obtained with desired environmental friendliness through the use of environmentally undesirable ammonia as a by-product.

For a better understanding of the present invention below are preferred examples and sample receipt. However, the examples are given only for illustration and in no way should be interpreted as limiting the scope of invention.

[Production examples 1-4: getting biureta]

In chetyrehosnuju round bottom flask was placed 500 g (8,33 mol) of urea, vigorously stirred and at the bottom of the bulb serves the air with speed, pointed to by the th in table 1. The reaction of lead for 5 hours at a temperature maintained at 140°by heating. After completion of the reaction the obtained solid composition analyzed by liquid chromatography, the results of the analysis are shown in table 1.

table 1
ExampleSpeedContentContentThe content of cyanuric
suppliedureabiuretaacid and other
air(wt.%)(wt.%)solids
(l/min)(wt.%)
1062353
2141554
3238602
4437612

[Production examples 5-7: getting biureta]

Biuret get in the same way as described in example 1, except that the reaction is carried out within chasov at different temperatures and air speeds, equal to 2 l/minute. After completion of the reaction composition obtained solids analyzed by liquid chromatography, the results of the analysis are shown in table 2.

table 2
ExampleThe reaction temperature (°)Urea concentration (wt.%)Content biureta (wt.%)The content of cyanuric acid and other solids (wt.%)
515047503
616038.5574.3
717028657

[Production examples 8-10: getting biureta]

Biuret get in the same way as described in example 1, except that the reaction is carried out at low pressures achieved using a vacuum pump, as shown in table 3, instead of the air supply. After completion of the reaction composition obtained solids analyzed by liquid chromatography, the result of analysis is shown in table 3.

table 3
ExamplePressure (mmrt. Art.)Urea concentration (wt.%)Content biureta (wt.%)The content of cyanuric acid and other solids (wt.%)
838056504
919041,5553.5
1010040573

[Production examples 11-13: getting biureta]

Biuret get in the same way as described in example 1, except that the reaction is carried out in the presence of 0.05 mole of catalyst per 1 mole of urea, and the blower speed is set to 2 l/minute. After completion of the reaction composition obtained solids analyzed by liquid chromatography, the result of analysis is shown in table 4.

table 4
ExampleCatalystContentContentThe content of cyanuric
ureabiuretaacid and other solid
(wt.%)(wt.%)substance (wt.%)
11Sulfuric acid34624
12Sodium phosphate36613
13Thionyl chloride35623

[Production example 14: synthesis of salts of carburet sodium]

In a glass reactor of 2 l put 423,1 g (0,287 mol) of 7% slurry solution biureta and cooled to a temperature of 5°under stirring. In the specified reactor add 12% aqueous sodium hypochlorite solution and the temperature of the reaction system is maintained at below 5°C. After complete addition, the reaction solution is analyzed by iodometry using liquid chromatography. The amount of chlorine is 3.37%, which corresponds to a yield of 98%.

[Production example 15: synthesis of salts of carburet sodium]

In a glass reactor of 2 l put 423,1 g (0,287 mol) slurry solution 7% biureta and with stirring, cooled to a temperature of 5°C. In the reactor add 223 g (0,575 mol) of 10.3% aqueous sodium hydroxide solution and 20.3 g (0,287 mol) of chlorine gas, maintaining the temperature of the reaction system below 10°C. After complete addition, the reaction solution is analyzed by iodometry and using liquid is based chromatography. The amount of chlorine is 3.0%, which corresponds to a yield of 98%.

[Production example 16: synthesis of the salt of carburet sodium]

In a glass reactor of 2 l put 423,1 g (0,287 mol) of 7% slurry solution biureta and cooled to a temperature of 5°under stirring. In the reactor type of 20.3 g (0,287 mol) of chlorine gas, maintaining the temperature of the reaction system at levels below 10°, followed by vigorously stirring 223 g (0,575 mol) of 10.3% aqueous sodium hydroxide solution, the reaction temperature is maintained at below 5°C. After complete addition, the reaction solution is analyzed by iodometry using liquid chromatography. The amount of chlorine is 3.0%, which corresponds to a yield of 98%.

[Examples 1-9: synthesis of hydrazodicarbonamide]

In the autoclave of 2 l put 593,1 g of salt carburet sodium obtained by the above production example 14, and is cooled to a temperature of 10°under stirring. Maintaining the temperature of the reaction solution below 10°C, With vigorous stirring, 600 g (8,8 mol) of 25% aqueous ammonia solution. The reaction is carried out by changing the temperature and time. After completion of the reaction the unreacted ammonia is removed, and the reaction solution is filtered to obtain insoluble in the ode hydrazodicarbonamide. The output of hydrazodicarbonamide calculated and are given in table 5.

table 5
ExampleReaction conditions (temperature, time)Output (%)
130°, 1 hour85
230°, 2 hours90
330°C, 3 hours89
460°, 1 hour91
560°, 2 hours89
660°C, 3 hours90
790°, 1 hour88
890°, 2 hours89
990°C, 3 hours90

[Examples 10-18: synthesis of hydrazodicarbonamide]

The reaction is carried out similarly as described in example 4, except that the added 0.05 mole of catalyst indicated in table 6. After completion of the reaction the unreacted ammonia is removed, and the reaction solution is filtered to obtain the water-insoluble hydrazodicarbonamide. The output of hydrazodicarbonamide calculated and are shown in table 6.

table 6
ExampleUsed catalystOutput (%)
10ZnCl294
11Zn(OH)292
12AlCl390
13BaCl291
14CdCl292
15ZnSO493
16ZnCl2+AlCl3(0,025 mol each)96
17ZnCl2+BaCl2(0,025 mol each)94
18ZnCl2+CdCl2(0,025 mol each)96

[Examples 19-27: synthesis of hydrazodicarbonamide]

In the autoclave of 2 l load 593,1 g of salt carburet sodium obtained by production example 15, and cooled to a temperature of 10°under stirring. Maintaining the temperature of the reaction solution below 10°C, With vigorous stirring, 600 g (8,8 mol) of 25% aqueous ammonia solution. The reaction is carried out by changing its temperature and time. After completion of the reaction the unreacted ammonia is removed and the reaction solution is filtered to obtain the water-insoluble hydrazodicarbonamide. The output gerstengarbe the amide calculated and shown in table 7.

table 7
ExampleReaction conditions (temperature, time)Output (%)
1930°, 1 hour78
2030°, 2 hours89
2130°C, 3 hours89
2260°, 1 hour88
2360°, 2 hours90
2460°C, 3 hours90
2590°, 1 hour87
2690°, 2 hours86
2790°C, 3 hours89

[Examples 28-36: synthesis of hydrazodicarbonamide]

The reaction is carried out similarly as described in example 22, except that the added 0.05 mole of catalyst are shown in table 8. After completion of the reaction the unreacted ammonia is removed and the reaction solution is filtered to obtain the water-insoluble hydrazodicarbonamide. The output of hydrazodicarbonamide calculated and are shown in table 8.

table 8
ExampleApply ka is alinator Output (%)
28ZnCl294
29Zn(OH)291
30AlCl389
31BaCl391
32CdCl393
33ZnSO492
34ZnCl2+AlCl3(0,025 mol each)97
35ZnCl2+BaCl2(0,025 mol each)93
36ZnCl2+CdCl2(0,025 mol each)96

[Examples 37-45: synthesis of hydrazodicarbonamide]

In the autoclave of 2 l load 593,1 g of salt carburet sodium obtained by the above production example 16, and cooled to a temperature of 10°under stirring. Maintaining the temperature of the reaction solution below 10°C, With vigorous stirring, 600 g (8,8 mol) of 25% aqueous ammonia solution. The reaction is carried out at different temperature and time regimes. After completion of the reaction the unreacted ammonia is removed and the reaction solution is filtered to obtain the water-insoluble hydrazodicarbonamide. The output of hydrazodicarbonamide calculated and are given in t the blitz 9.

table 9
ExampleReaction conditions (temperature, time)Output (%)
3730°, 1 hour79
3830°, 2 hours88
3930°C, 3 hours89
4060°, 1 hour89
4160°, 2 hours90
4260°C, 3 hours91
4390°, 1 hour88
4490°, 2 hours88
4590°C, 3 hours89

[Examples 46-54: synthesis of hydrazodicarbonamide]

The reaction is carried out similarly as described in example 40, except that added 0.05 mole of catalyst indicated in table 10. After completion of the reaction the unreacted ammonia is removed and the reaction solution is filtered to obtain the water-insoluble hydrazodicarbonamide. The output of hydrazodicarbonamide calculated and are given in table 10.

table 10
ExampleUsed cat the lyst Output (%)
46ZnCl293
47Zn(OH)290
48AlCl390
49BaCl290
50CdCl292
51ZnSO489
52ZnCl2+AlCl3(0,025 mol each)95
53ZnCl2+BaCl2(0,025 mol each)93
54ZnCl2+CdCl2(0,025 mol each)94

[Examples 55-58: synthesis of hydrazodicarbonamide]

In the autoclave of 2 l put 593,1 g of salt carburet sodium obtained by the above production example 14, and is cooled to a temperature of 10°under stirring. Maintaining the temperature of the reaction solution below 10°C, With vigorous stirring for one hour add aqueous ammonia in amounts shown in table 11. After completion of the reaction the unreacted ammonia is removed and the reaction solution is filtered to obtain the water-insoluble hydrazodicarbonamide. The output of hydrazodicarbonamide calculated and are shown in table 11.

table 11
ExampleThe molar ratio of ammonia to salts of carburet sodium (%)Output (%)
551575
563087
576090
589089

[Examples 59-62: synthesis of hydrazodicarbonamide]

In the autoclave of 2 l load 593,1 g of salt carburet sodium obtained by the above production example 14, is cooled to a temperature of 10°under stirring and add organic solvent indicated in table 12, in the amount equal to 0.5 by weight of water. Maintaining the temperature of the reaction solution below 10°C, With vigorous stirring for one hour add 600 g of 25% aqueous ammonia solution. After completion of the reaction the unreacted ammonia is removed and the reaction solution is filtered to obtain the water-insoluble hydrazodicarbonamide. The output of hydrazodicarbonamide calculated and are shown in table 12.

table 12
ExampleUsed solventOutput (%)
59Methanol90
60Dimethylformamide94
61Tetrahydrofuran90
62Acetonitrile88

As described above, in accordance with the present invention hydrazodicarbonamide can be synthesized using the method and device of manufactured and readily available urea as the source of the product. In addition, by reducing the amount of byproduct and source material hydrazodicarbonamide can be obtained cost-effective way and with the desired environmental, and due to the continuity of the process, with high efficiency.

1. The method of producing hydrazodicarbonamide, including the stage of obtaining the biureta formula 1 and ammonia by pyrolysis of urea; obtaining metal salt of monohalogenated formula 2 or 3 way interaction obtained biureta connection metal hypogalactia or halogen and a base; the interaction of the obtained metal salt of monohalogenated with ammonia, including ammonia, obtained in the pyrolysis of urea at a molar ratio of metal salt of monohalogenated and total ammonia of 1:1˜1:1000.

where M represents a metal, X represents halogen;

carried out on the device to obtain hydrazodicarbonamide, including pyrolysis furnace to obtain biureta and ammonia by pyrolysis of urea; reactor for recrystallization to clean biureta obtained in the pyrolysis furnace; a first reactor to obtain a metal salt of monohalogenated when interacting biureta connection metal hypogalactia or halogen and the base; a second reactor for the synthesis of hydrazodicarbonamide when interacting metal salt of monohalogenated with ammonia; ammonia evaporator for separating excess ammonia from hydrazodicarbonamide and dedicated delivery of ammonia to ammonium hub, with ammonia hub is designed for the concentration of excess ammonia and ammonia obtained in the pyrolysis furnace, and to deliver concentrated ammonia in the second reactor.

2. The method of producing hydrazodicarbonamide according to claim 1, where the temperature pyrolysis of urea is in the range of 100-300°C.

3. The method of producing hydrazodicarbonamide according to claim 1, where the pyrolysis of urea is performed with the removal of ammonia from the reaction system.

4. The method of producing hydrazodicarbonamide according to claim 1, where the pyrolysis of urea is carried out using inert gas and/or by reducing the pressure the Oia in the reaction system.

5. The method of producing hydrazodicarbonamide according to claim 1, where the pyrolysis of urea is carried out in the presence of at least one catalyst selected from the group consisting of inorganic acid catalyst and acid catalyst type and compounds containing phosphorus.

6. The method of producing hydrazodicarbonamide according to claim 1, where the molar ratio of biureta and connections metal hypogalactia in the process is 1:0.1 to 1:2.

7. The method of producing hydrazodicarbonamide according to claim 1, where the salt of the metal of monohalogenated prepared by mixing a metal hydroxide with bureta formula 1 with the subsequent interaction of the obtained product with halogen or produced by the interaction biureta formula 1 with gaseous halogen, followed by mixing the resulting product with a base.

8. The method of producing hydrazodicarbonamide according to claim 1, where the process of obtaining a metal salt of monohalogenated carried out at a temperature below 60°C.

9. The method of producing hydrazodicarbonamide according to claim 1, where the ammonia is liquid or gaseous ammonia or ammonium hydrate.

10. The method of producing hydrazodicarbonamide according to claim 1, where the reaction of the metal salt of monohalogenated with ammonia is carried out in the temperature range 0-150°C.

11. The method of producing hydrazodicarbonamide according to claim 1, where the solvent of the reaction is mixture is water and the second solvent, and the second solvent is a polar solvent selected from the group consisting of water, methanol, ethanol, propanol, isopropanol and their mixtures or aprotic solvent selected from the group consisting of dimethylformamide, dimethyl sulfoxide, dimethylacetamide and mixtures thereof.

12. Device for receiving hydrazodicarbonamide, including pyrolysis furnace to obtain biureta and ammonia by pyrolysis of urea; reactor for recrystallization to clean biureta obtained in the pyrolysis furnace; a first reactor to obtain a metal salt of monohalogenated when interacting biureta connection metal hypogalactia or halogen and the base; a second reactor for the synthesis of hydrazodicarbonamide when interacting metal salt of monohalogenated with ammonia; ammonia evaporator for separating excess ammonia from hydrazodicarbonamide and dedicated delivery of ammonia to ammonium hub, with ammonia hub is designed for the concentration of excess ammonia and ammonia obtained in the pyrolysis furnace, and for delivery of concentrated ammonia in the second reactor.

13. Device for receiving hydrazodicarbonamide indicated in paragraph 13, where the pyrolysis furnace has a gas injector for supplying an inert gas that does not interact with isocyanates acid in the pyrolysis furnace.

14. Device for receiving hydrazodicarbonamide indicated in paragraph 13, where the pyrolysis furnace has the technical means to reduce the pressure to remove ammonia from the pyrolysis furnace.



 

Same patents:

The invention relates to new chemical compound 1,5-bis-(2-hydroxyethyl)-biuret, or diethanolamine, and method thereof

FIELD: chemical industry; methods and the devices for production of the biuret.

SUBSTANCE: the invention is pertaining to the method of production of biuret and to the device for its realization. The process includes production in the pyrolysis furnace of the biuret and ammonia by the carbamide pyrolysis, purification of the gained biuret in the reactor of the recrystallization, production of the salt of the monohalogenbiuret metal by interaction of the biuret with the compound of the hypohalogen metal or with halogen and the base in the first reactor. Interaction in the second reactor of the produced biuret metal salt with ammonia, including the ammonia produced during the pyrolysis process of carbamide at the molar ratio of the salt of the monohalogenbiuret metal and the total amount of the ammonia making 1:1-1:1000. The separated excess of the ammonia extracted from biuret in the ammonia evaporator is sent to the ammonia concentrator. At that the ammonia concentrator is intended for concentration of the excess of the ammonia and the ammonia produced in the pyrolysis furnace and for delivery of the concentrated ammonia in the second reactor. The technical result of the invention is the development of the economically profitable continuous process with high efficiency and utilization of the easily accessible source product, reduction of the quantity of the by-products.

EFFECT: the invention ensures the development of the economically profitable continuous process with high efficiency and utilization of the easily accessible source product, reduction of the quantity of the by-products.

14 cl, 62 ex, 12 tbl

FIELD: chemical industry; methods and the devices for production of the biuret.

SUBSTANCE: the invention is pertaining to the method of production of biuret and to the device for its realization. The process includes production in the pyrolysis furnace of the biuret and ammonia by the carbamide pyrolysis, purification of the gained biuret in the reactor of the recrystallization, production of the salt of the monohalogenbiuret metal by interaction of the biuret with the compound of the hypohalogen metal or with halogen and the base in the first reactor. Interaction in the second reactor of the produced biuret metal salt with ammonia, including the ammonia produced during the pyrolysis process of carbamide at the molar ratio of the salt of the monohalogenbiuret metal and the total amount of the ammonia making 1:1-1:1000. The separated excess of the ammonia extracted from biuret in the ammonia evaporator is sent to the ammonia concentrator. At that the ammonia concentrator is intended for concentration of the excess of the ammonia and the ammonia produced in the pyrolysis furnace and for delivery of the concentrated ammonia in the second reactor. The technical result of the invention is the development of the economically profitable continuous process with high efficiency and utilization of the easily accessible source product, reduction of the quantity of the by-products.

EFFECT: the invention ensures the development of the economically profitable continuous process with high efficiency and utilization of the easily accessible source product, reduction of the quantity of the by-products.

14 cl, 62 ex, 12 tbl

FIELD: chemistry.

SUBSTANCE: method of producing biuret and cyanuric acid through thermal decomposition of urea involves cooling the product of thermal decomposition of urea in order to settle crystals which are then dissolved in an aqueous alkaline solution and cooled to obtain high-purity biuret, and after neutralising the filtered mother solution with acid, cyanuric acid crystals are settled to obtain a suspension of cyanuric acid crystals which is then filtered to separate the crystals and washed. The invention also relates to devices for realising the given methods.

EFFECT: development of a cheap and simple method of producing biuret and high-purity cyanuric acid.

19 cl, 2 ex, 1 dwg

FIELD: chemistry.

SUBSTANCE: polyisocyanate contains biuret groups, has functionality on isocyanate groups of not less than 4 and not more than 10 and is obtained using a method which includes (A) reaction of a polyisocyanate adduct with a secondary monoamine of formula (R1)(R2)NH, with the ratio of the isocyanate equivalent to the amine equivalent ranging from approximately 4:1 to approximately 14:1 to introduce biuret groups into said polyisocyanate, and (B) reaction of the polyisocyanate containing biuret groups with a blocking reagent. The polyisocyanate adduct (a) is obtained from 1,6-hexamethylenediisocyanate, (b) has average functionality on isocyanate groups of not less than 2.5 and not more than 8, and (c) contains isocyanurate groups. The blocking reagent is selected from a group comprising phenol, cresol, amides, oximes, hydrazones, pyrazoles and phenols which are substituted with long aliphatic chains.

EFFECT: obtaining blocked polyisocyanates which combine relatively low viscosity and low molecular weight with high functionality on isocyanate groups and high reactivity relative to binders used in coatings, as well as which are stable during storage with respect to increase in viscosity and are virtually colourless, which is especially important for systems which form transparent coatings.

9 cl, 6 ex, 5 tbl

FIELD: chemistry.

SUBSTANCE: described is a polymerisable iodonium salt containing a positively charged iodine atom bonded with two aryl rings and a negatively charged counter-ion and at least one substitute containing a urethane and/or urea group, which is bonded with at least one of said aryl rings, wherein said substitute contains at least one functional group capable of cationic or radical polymerisation. Described also is a polyvinyl alcohol acetal copolymer containing at least one functional group, which is capable of cationic or radical polymerissation, preferably vinyl ether, alkoxy-methylacrylamide or alkoxy-methacrylamide. The invention also describes polymer binder for coating an offset printing plate from the polyvinyl alcohol acetal family, cellulose ether family and binder based on monomers, each containing at least one functional group capable of cationic or radical polymerisation. Described also is an offset printing plate coating solution containing said polymerisable iodonium salt, said polyvinyl alcohol acetal copolymer and said binder.

EFFECT: high quality of high-resolution image when the offset printing plate is used repeatedly.

17 cl, 25 dwg, 21 ex

Up!