CN107922191B

CN107922191B - Method for cleaving azine bond or hydrazone bond

Info

Publication number: CN107922191B
Application number: CN201580082178.8A
Authority: CN
Inventors: 谷口正俊
Original assignee: Mitsubishi Gas Chemical Co Inc
Current assignee: Mitsubishi Gas Chemical Co Inc
Priority date: 2015-08-03
Filing date: 2015-08-03
Publication date: 2020-10-16
Anticipated expiration: 2035-08-03
Also published as: WO2017022063A1; JP6500990B2; JPWO2017022063A1; CN107922191A

Abstract

The present invention relates to a method for producing hydrazine hydrate, substituted hydrazine or an amino compound, which is characterized in that a ketone, hydrazine hydrate or substituted hydrazine, or hydrazinoformic acid or substituted hydrazinoformic acid, or a carbonyl compound and an amino compound, or a carbamic acid compound or substituted carbamic acid is obtained by hydrolyzing a ketone azine, hydrazone or schiff base compound in the presence of carbon dioxide in the subcritical, supercritical or liquid carbon dioxide state.

Description

Method for cleaving azine bond or hydrazone bond

Technical Field

The present invention relates to a production method for cleaving an azine bond, a hydrazone bond, and an azomethine bond of an azine compound with liquid carbon dioxide, supercritical carbon dioxide, or subcritical carbon dioxide, thereby suppressing the production of by-products with low energy and easily obtaining hydrazinoformic acid (hydrazine hydrate), substituted hydrazine, hydrazinoformic acid derivatives, carbamic acid derivatives, and amino compounds.

Background

Hydrazines hydrate are used for: an action of removing oxygen dissolved in boiler water to prevent boiler corrosion, a raw material of a blowing agent for a resin, a polymerization initiator for a polymer, a raw material of a gas generating agent for an air bag, a raw material for various drugs, a raw material for agricultural chemicals, a rocket fuel, a fuel for controlling attitude of a satellite, a production use of fine metal particles for an electronic material, an etching agent for a circuit board, and the like are important compounds in a wide range. In addition, substituted hydrazines, carbamic acid derivatives, and hydrazinoformic acid derivatives are important compounds as synthetic raw materials and reaction reagents for drugs, pesticides.

[ description of conventional Process ]

The description will be made centering on hydrazine hydrate and substituted hydrazine. The production of hydrazine hydrate and substituted hydrazines is a technology that has been developed and commercialized since a long time ago. The technology used in production is the old technology developed in the past, and there is no new promising technology. Although local minor technical improvements were also made, the basic reaction was not completely improved. The manufacturing method which has been conventionally and currently carried out is basically the following method.

As the method 1, there is a method called a urea method. (non-patent document 1)

The method comprises the following steps: urea is converted into urea chloride or substituted urea chloride by a chlorinating agent (oxidizing agent) such as sodium hypochlorite, amino isocyanate is generated by hofmann rearrangement, and hydrazine hydrate or substituted hydrazine is obtained by hydrolysis (reaction formula 1). The method has a disadvantage in that hydrazine hydrate or substituted hydrazine is a very strongly reducing compound, and thus the produced hydrazine hydrate or substituted hydrazine is immediately decomposed when the oxidizing agent-sodium hypochlorite coexists in the system in the raw materials. Therefore, a stabilizer such as a gum is added to the reaction system, and in the case of hydrazine hydrate, it is necessary to stop the reaction and separate it in a low concentration of 4% or less. The hydrazine hydrate or substituted hydrazine of not more than 4% is concentrated and separated from inorganic salts which are by-products produced in large amounts, and the by-products of inorganic salts become waste. Furthermore, in the case of hydrazine hydrate, it is necessary to concentrate the hydrazine hydrate to 60 to 100% of the concentration of the practical product. In the case of anhydrous hydrazine, 100% hydrazine hydrate must first be obtained. And therefore consumes a large amount of energy. There is also a method of converting hydrazine hydrate or substituted hydrazine into a salt of an inorganic acid and then concentrating the salt, and there is also a method of stabilizing the produced hydrazine as an inorganic salt in order to obtain a desired hydrazine hydrate or substituted hydrazine. At this time, a large amount of inorganic salt waste is also generated.

[ reaction formula 1]

As the method 2, there is a method called Raschig (Raschig) method as follows: ammonia or substituted amines are reacted with a chlorinating agent (oxidizing agent) such as sodium hypochlorite to produce chloramine, and the chloramine is reacted with the ammonia or an amine derivative at a low temperature to obtain hydrazine hydrate or substituted hydrazine (reaction formula 2). Hydrazine hydrate or substituted hydrazine generated in this reaction is a very strong reducing agent, and reacts with an oxidizing agent, i.e., a chlorinating agent (sodium hypochlorite) to decompose the generated hydrazine hydrate or substituted hydrazine. In order to avoid this, it is also necessary to add a gum or the like to the process for stabilization, stop the reaction at a low concentration of 4% or less of the concentration of hydrazine hydrate or substituted hydrazine produced, separate the reaction product from the inorganic salt by-produced, and concentrate the reaction product to 60 to 100% of the concentration of hydrazine hydrate or substituted hydrazine normally used in the case of hydrazine hydrate. In addition, in order to obtain anhydrous hydrazine, 100% hydrazine hydrate must be obtained first. In this case, a large amount of energy is consumed, and a large amount of by-product salt is generated, which causes problems and pollution. There is also a method of stabilizing the produced hydrazines by converting them into inorganic salts, but it is necessary to neutralize the inorganic salts and convert them into hydrazine hydrate or substituted hydrazines. In this case, a large amount of inorganic salt waste is also generated (non-patent document 2).

[ reaction formula 2]

The following methods have been developed to improve the disadvantages of the method 1, urea method, and Raschig method, in which hydrazine hydrate or substituted hydrazine produced is decomposed by a chlorinating agent (sodium hypochlorite), which is an oxidizing agent in the raw material, and the reaction is stopped at a low concentration to obtain only hydrazine hydrate or substituted hydrazine at a low concentration.

The method 3 is a method called an organic method or a ketazine method, and includes the following steps: in the reaction of the Raschig method, under the existence of large excess ammonia water or amine derivatives and large excess acetone, a small amount of oxidant, namely chlorinating agents such as sodium hypochlorite and the like are dripped at each time under low temperature and vigorous stirring, so that the dispersion and diffusion of the sodium hypochlorite aqueous solution are promoted, and the reaction with ammonia is promoted. The produced low-concentration hydrazine hydrate or substituted hydrazine is immediately reacted with acetone having a very high reactivity with hydrazine or substituted hydrazine to be converted into chemically stable acetone azine or acetone substituted hydrazone, so that it is not oxidized by a chlorinating agent (oxidizing agent), but the decomposition reaction by an oxidizing agent, i.e., sodium hypochlorite is fast and no significant effect is obtained (reaction formula 3). Acetone hydrazone protects only one of them, and therefore the other free hydrazine group is easily oxidized as well as hydrazine hydrate, and therefore cannot be a protected compound which is not oxidized by an oxidizing agent such as sodium hypochlorite. If the hydrazine group in the hydrazine hydrate at both ends or the substituted hydrazine does not react with acetone to form ketazine or hydrazone of the substituted hydrazine, oxidative decomposition by an oxidizing agent cannot be avoided (patent document 1).

[ reaction formula 3]

However, there is a problem that a large amount of salt is by-produced; and, before forming acetone azine or acetone-substituted hydrazone for stabilization, the strong reducing property of the produced hydrazine hydrate or substituted hydrazine and the reaction rate of the chlorine-based oxidizing agent are fast, and the produced hydrazine hydrate or substituted hydrazine is decomposed by the chlorine-based oxidizing agent of the oxidizing agent. Therefore, in the case of hydrazine hydrate, the concentration of ketazine or substituted hydrazone in the reaction system is limited to about 5% in terms of hydrazine hydrate, as in the case of the methods 1 and 2. Acetone azine is water-soluble, and after the reaction, excess ammonia is recovered by evaporation, then excess acetone with a low boiling point is recovered by evaporation, and finally, acetone azine is azeotroped and separated with water. An aqueous solution having a high salt concentration and containing impurities remains at the bottom of the distillation column, and is generally discarded, thereby causing pollution. The concentration of the acetone azine obtained here is at most about 20% in terms of hydrazine hydrate. Acetone hydrazone or acetone substituted hydrazone is insoluble in water and does not azeotrope with water. Other methods are required for the isolation and purification of acetone azine. The ketazine method is characterized by forming stable azine or substituted hydrazone which is not oxidized by a chlorinating agent which is an oxidizing agent, but in order to obtain hydrazine hydrate or substituted hydrazine which is a desired target, it is necessary to hydrolyze the obtained ketazine or hydrazone or substituted hydrazone to obtain hydrazine hydrate or substituted hydrazine, and hydrolysis with a strong acid such as sulfuric acid or hydrochloric acid is easy. However, the obtained product can be obtained only from hydrazine hydrate, hydrazine derivatives, and salts thereof. Neutralization is necessary to obtain free hydrazine hydrate, hydrazine itself. As a result, additional alkali raw material is required and a large amount of by-product salt is produced. Stable ketazine, hydrazone, and substituted hydrazone are very difficult to hydrolyze without using strong acids and the like. Other ketones do not exhibit as high a reactivity as acetone and therefore do not have the effect of hydrazine-based protectors and cannot be used. High concentrations of hydrazine hydrate and substituted hydrazines cannot be used in most industrial applications without hydrolyzing the ketone azine, hydrazone, and acetone substituted hydrazone. There are also examples of using low concentrations of hydrazine hydrate or substituted hydrazines in special cases. As a method for hydrolyzing acetone azine or acetone hydrazone without using a strong acid or the like, a method of hydrolysis at a high temperature is considered, but since the reaction rates of hydrolysis reaction and recombination of the hydrolyzed compounds are almost the same in an equilibrium reaction, it is very difficult to obtain a target product by hydrolysis at a high temperature. When the high-temperature pyrohydrolysis method is applied to the hydrolysis of ketone azine, hydrazone and acetone-substituted hydrazone obtained by the preparation method, the high-temperature pyrohydrolysis at about 150-160 ℃ is needed, and the target object is obtained little by utilizing the extremely small difference of equilibrium constants, so that the method has the serious problems of very poor efficiency and large energy consumption. However, it has an advantage that a large amount of by-products are not produced and cause of pollution. This method will be described in detail later.

A method developed as the 4 th method is a method called a hydrogen peroxide method (patent document 2) (patent document 3).

Any of the methods 1, 2 and 3 produces a large amount of by-product salt, which causes pollution. In addition, in order to avoid decomposition of the product by an oxidizing agent such as sodium hypochlorite in the raw material, it is necessary to stop the reaction at a low concentration. As a method for preventing the formation of a large amount of by-product salt, a method using hydrogen peroxide as an oxidizing agent has been developed. Although the reaction mechanism is not disclosed, it is completely different from that of the conventional production method based on the knowledge of chemical reaction, and the reaction mechanism can be easily presumed. However, it is not simply mixed with hydrogen peroxide. At present, no document exists for confirming and explaining reaction intermediates and reaction mechanisms. We speculate that: the putative reaction is preferably first reacting the ketone with ammonia to form a stable ketimine (ketimine). It is preferable that the ketimine (ketimine) forming ketone is reactive with ammonia or an amine derivative, and the ketimine (ketimine) formed by the reaction with the ketone is instead a stable compound. Acetone used in the method 3 produces acetonimine, but the acetonimine or the acetonimine derivative is unstable, and therefore the acetonimine or the acetonimine derivative is avoided from the viewpoints of difficulty in handling, yield, side reactions, and decomposition reactions. In this technique, any ketone may be used as long as it can form a stable ketimine, but 2 molecules of ketimine are oxidized with hydrogen peroxide to form a ketiazine or a substituted hydrazone. The same problem as that shown in the method 3 arises. When ketone azines are hydrolyzed with strong acids, hydrazine salts or substituted hydrazine salts are obtained. It is desirable to obtain hydrazine hydrate or substituted hydrazine by a high-temperature pyrohydrolysis method without generating a by-product salt which causes pollution and without using a strong acid which increases the cost. From the viewpoint of pyrohydrolysis and post-treatment of ketazine and substituted hydrazone, a stable methyl ethyl ketimine (ketimine) is obtained by reacting methyl ethyl ketone with ammonia or an amine derivative, and the ketimine is oxidized with hydrogen peroxide in the presence of a catalyst (tetramethyldiarsene) containing a strongly toxic arsenic compound to bond the NH structure of 2 molecules of the ketimine to form an N-N bond, thereby producing a ketoazine; or the ketimine is combined with the substituted amine through the same reaction to obtain substituted hydrazone; the methyl ethyl ketazine or substituted hydrazone thus obtained is a ketone azine or hydrazone or substituted hydrazone that is further more stable than acetone azine or acetone hydrazone derivatives. In order to obtain the target hydrazine hydrate or substituted hydrazine, it is necessary to hydrolyze the ketone azine and substituted hydrazone obtained herein (reaction formula 4).

[ reaction formula 4]

The high temperature thermal hydrolysis of the stabilized ketoazine or hydrazone or substituted hydrazone to obtain hydrazine hydrate or substituted hydrazine is difficult to achieve in processes 3 and 4. In the 3 rd and 4 th methods, when the produced hydrazone is subjected to a high-temperature pyrohydrolysis reaction, the hydrolysis is changed into more by-products of intramolecular reactions or by-products of reactions of the hydrazone with a ketone. The ketone used in the method 4 is mainly methyl ethyl ketone or the like from the viewpoints of imine formation, stability, reactivity, and the like, and from the viewpoint of the balance of thermal hydrolyzability of the ketone azine or substituted hydrazone after the reaction and regeneration into a ketone by hydrolysis and the like. The methylethylketone azine, methylethylhydrazone, methylethyl-substituted hydrazone, or the like obtained therefrom is insoluble in water, and therefore has an advantage that it can be easily separated from a water layer, and an advantage that inorganic salt waste such as common salt is not generated, but it is necessary to use a highly toxic arsenic catalyst and to conduct pyrohydrolysis at a high temperature of about 190 ℃. Therefore, it is more difficult to implement the method because of problems such as a large amount of energy waste, by-product generation during high-temperature heating, and coloring of the product. Furthermore, the pyrohydrolysis of ketazine is nearly impossible when ketones with a large number of carbon atoms are used. The hydrolysis reaction thereof will be described in detail in the following items.

[ description of the method for the high-temperature pyrohydrolysis of Ketoprazone, hydrazone, or substituted hydrazone in the production method for obtaining Ketoprazone, hydrazone, or substituted hydrazone ]

In the 3 rd process (organic process, ketazine process), the reduction of the produced hydrazine hydrate or substituted hydrazine is very strong before the formation and stabilization of the acetone azine, and therefore the produced hydrazine hydrate or substituted hydrazine is easily oxidized and decomposed by a chlorinating agent such as sodium hypochlorite which is an oxidizing agent in the raw material, and therefore the produced hydrazine hydrate or substituted hydrazine is converted into the stable acetone azine or acetone-substituted hydrazone before the decomposition of the oxidizing agent, and is not oxidized and decomposed. In acetone hydrazone, on the other hand, the hydrazine group is in a free state, and therefore, the acetone hydrazone is easily oxidized by the raw material oxidizing agent and cannot form a stabilized substance. On the other hand, although hydrazine hydrate or substituted hydrazine can be used in a low concentration state, basically, as the concentration of acetone azine, acetone hydrazone or acetone substituted hydrazone increases, hydrazine hydrate or substituted hydrazine produced later has a high reaction rate with a chlorine-based oxidizing agent such as sodium hypochlorite, and thus a decomposition reaction by the oxidizing agent occurs preferentially. Thus, the acetone azine or acetone substituted hydrazone method also requires stopping the reaction at a low concentration. The final desired product is essentially a high concentration of hydrazine hydrate or substituted hydrazine except for the particular application, and thus it is necessary to hydrolyze and concentrate the ketoazine compound or substituted hydrazone to produce a high concentration of hydrazine hydrate or substituted hydrazine.

In the case of the 4 th process (hydrogen peroxide process), the following is conceivable from the viewpoint of the presumed reaction mechanism: methyl ethyl ketone is reacted with ammonia or a substituted amine to produce methyl ethyl ketimine, and the methyl ethyl ketimine is oxidized with hydrogen peroxide in the presence of an arsenic-based catalyst to produce an N-N bond, which is initially converted to methyl ethyl ketone azine or methyl ethyl substituted hydrazone. Since hydrazine hydrate or substituted hydrazine is not produced at the beginning of the reaction, there is no problem that the hydrazine hydrate or substituted hydrazine is decomposed by the oxidizing agent, i.e., hydrogen peroxide. The concentration of methyl ethyl ketone azine or methyl ethyl substituted hydrazone can be increased, but these compounds are extremely stable compounds. The final target product is a high-concentration product of hydrazine hydrate or substituted hydrazine, and therefore, it is necessary to hydrolyze methyl ethyl ketone azine or methyl ethyl substituted hydrazone compound to hydrazine hydrate or substituted hydrazine, recover methyl ethyl ketone, and concentrate the hydrazine hydrate or substituted hydrazine.

In both processes of the 3 rd and 4 th processes, the hydrolysis of the ketone azine or substituted hydrazone is necessary because a stable substance of the ketone azine or substituted hydrazone is obtained. Although hydrolysis can be easily performed by using an inorganic acid or the like as a catalyst, the obtained compound is an inorganic acid salt of hydrazine or substituted hydrazine, and it is necessary to form hydrazine hydrate or substituted hydrazine by neutralization with a base again, and therefore a large amount of by-product salt is further generated, which causes pollution, and the cost is increased by using an additional neutralized raw material.

To avoid this, a high-temperature pyrohydrolysis method is adopted in actual production, and this method does not produce a by-product salt from a highly stable ketazine or substituted hydrazone. However, the rate constant of the recombination reaction of the ketone produced by high-temperature pyrohydrolysis and hydrazine hydrate or substituted hydrazine also increases. Is an equilibrium reaction with no difference in reaction rate. Even the best conditions are chosen, only very small amounts of hydrazine hydrate or substituted hydrazine are obtained (equation 5).

The hydrolysis reaction constant becomes large when the thermal hydrolysis reaction is carried out at a higher temperature, but the reaction rate constant of the ketone with the free hydrazine hydrate or the substituted hydrazine becomes large, which are conditions that contradict each other. Since there are temperature points with slightly different equilibrium constants in the high-temperature pyrohydrolysis, the amount of hydrazine hydrate or substituted hydrazine that can be separated by the high-temperature pyrohydrolysis is extremely small, but the ketazine or substituted hydrazone is infinitely circulated at the high temperature to pyrohydrolyze and obtain the hydrazine hydrate or substituted hydrazone at a low concentration. When the hydrolysis temperature is further gradually increased, the difference in the reaction rate constant does not become large accordingly. Hydrolysis of acetone azine or acetone-substituted hydrazone (preparation 3) requires a minimum of about 150 ℃ and 160 ℃ and hydrolysis of methyl ethyl ketone azine or methyl ethyl ketone-substituted hydrazone (preparation 4) requires a minimum of about 180 ℃ and 190 ℃. Other ketones are less able to undergo the formation of ketazine or substituted hydrazone and the thermal hydrolysis of these compounds. Since the pyrohydrolysis is performed for a long period of time to obtain hydrazine hydrate or substituted hydrazine, a large amount of energy waste is generated and hydrazone is generated due to an incomplete reaction at the time of ketoazination at the time of synthesis of the ketoazine and is generated by incomplete decomposition and recombination at the time of pyrohydrolysis. Upon heating, the hydrazone undergoes a disproportionation reaction to form ketone azine and hydrazine hydrate, and the hydrazone of hydrazine hydrate and ketone is an unstable compound and generates a large amount of pyrazoline and other by-products in the high-temperature heating process by an intramolecular reaction or a reaction with ketone. Furthermore, the ketones themselves can form condensates over a long period of time at high temperatures. In addition, these by-products are responsible for the reduction in purity and coloration of the product. The high-temperature heating hydrolysis method has a problem that energy consumption is extremely large and economical efficiency is poor, and only a low-quality product containing impurities and having coloring is obtained. The concentration of hydrazine hydrate obtained by high-temperature pyrohydrolysis in the ketazine method, the salts produced as a by-product, the method for separating the same, the method for concentrating the same, and the like are described in the items. Either method requires distillative purification and, if desired, re-rectification.

[ reaction formula 5]

K1 and K2 represent dissociation constants.

Documents of the prior art

Patent document

Patent document 1 Ger. P.1,082,889(June 9,1960)

Patent document 2 FR.P.2260569(November,5,1975)

Patent document 3 US.P.4093656(June.6.1978)

Non-patent document

Non-patent document 1 J.Fischer, J.Jander, Z.Anorg.Allgem.chem.,313,14(1961)

Non-patent document 2 J.E.Troyan, Ind.Eng.chem.,45,2608(1953)

Non-patent document 3 journal of the Association of forestry and Hongyong and organic Synthesis chemistry, pp 33 and 451 (1975)

Non-patent document 4 "teaching material for liquefied carbon dioxide treatment" of the Japan Industrial & medical gas Association "(9.2015, 54 p. 9)

Disclosure of Invention

Problems to be solved by the invention

The present invention addresses the problem of providing a method for producing hydrazine hydrate or substituted hydrazine, which does not use a catalyst such as an inorganic acid, does not produce by-products or waste products, consumes little energy, and can economically produce hydrazine hydrate or substituted hydrazine with high purity, high concentration, and arbitrary concentration by hydrolyzing a ketazine (ketazine) or hydrazone, substituted hydrazone, or schiff base compound at low temperatures such as normal temperature with high yield and high efficiency. In addition, compounds having a carbonyl group such as ketones and aldehydes used as raw materials can be widely used. The carbon dioxide used can be recycled. In addition, in the conventional method, in the method of hydrolyzing a ketone azine compound or a ketone-substituted hydrazone compound to generate hydrazine hydrate or substituted hydrazine without using a catalyst such as an inorganic acid, high-temperature pyrohydrolysis is required, and therefore, the ketone compound that can be substantially used is limited to acetone or methyl ethyl ketone. Further, if a large amount of by-produced salt is allowed, it is also possible to obtain hydrazine hydrate or substituted hydrazine by hydrolyzing with an inorganic acid to obtain an inorganic acid salt of hydrazine and then neutralizing. However, they have a decisive disadvantage of being poor in economical efficiency and causing pollution due to the production of a large amount of by-produced salt. Although a wide range of carbonyl compounds can be used, it is difficult to use them as a substantial production method.

The process of the present invention is a completely different hydrolysis mechanism and therefore enables the use of a wide range of carbonyl compounds.

Means for solving the problems

The present inventors have conducted extensive studies on the search for a compound which can be expected to exhibit a catalytic effect in the hydrolysis of a ketoazine, hydrazone, substituted hydrazone, or schiff base compound and a method for using the same in order to solve the above-mentioned problems, and as a result, the conversion rate is low and only a low concentration of hydrazine hydrate or substituted hydrazine can be obtained in spite of the fact that the hydrolysis reaction proceeds with an acidity of such a degree that carbon dioxide is dissolved by a lewis acid, ordinary carbonated water, or pressure. When the temperature of the hydrolysis reaction is increased, the reaction is promoted to some extent, but the side reaction is also promoted. The object of the present invention cannot be achieved. Although carbonic acid is considered as an acid which does not form a stable salt with hydrazine hydrate or substituted hydrazine and does not form a salt which needs to be separated and discarded, the pH of carbonated water at normal temperature and normal pressure is 6.35, and the pH decreases when the solubility is increased by pressurization, but the limit is about pH 2.9. At this degree of acidity, the hydrolysis of azines or hydrazones or substituted hydrazones is very weak. Even if the reaction is carried out at a high temperature under pressure in order to improve the reactivity, the amount of by-products is increased, and the production of the target hydrazine hydrate or substituted hydrazine is not increased so much. As will be described in detail later, carbon dioxide is in a carbon dioxide state, a subcritical region, a supercritical state, and a liquid carbon dioxide state depending on pressure and temperature. Surprisingly, it has been found that an azine, hydrazone, substituted hydrazone, or schiff base compound is successfully hydrolyzed under the conditions of carbon dioxide in a subcritical or supercritical state under the lowest pressure condition and further liquid carbon dioxide in a phase diagram and in the presence of water without producing impurities, and that a target hydrazine hydrate, substituted hydrazine, or a carbonyl compound and an amino compound can be produced in a short time with high yield and high efficiency.

We have found that, in order to form hydrazine hydrate, substituted hydrazine, a carbonyl compound or an amino compound from a ketone azine, hydrazone, substituted hydrazone or schiff base compound by hydrolysis using subcritical or supercritical carbon dioxide and liquid carbon dioxide, a solution in which a required amount of water and an amount of water equal to or more than that required for the hydrolysis reaction are added as a hydrate and a dispersion are stirred and mixed under mild conditions of 40 ℃ or less, whereby hydrazine hydrate, hydrazinoformic acid (hydrazinoformic acid), substituted hydrazine, substituted hydrazinoformic acid, a carbamic acid derivative or a carbonyl compound and an amino compound having a high purity and a high concentration and having an arbitrary concentration by adjusting the amount of water can be efficiently obtained.

Although this unexpected reaction mechanism is assumed, the association of liquid carbon dioxide and supercritical carbon dioxide that is neither gas nor liquid is not a single molecule gas but a state in which a plurality of molecules are associated when microscopic observation is performed, and it is presumed that the action mechanism is an electron transfer mechanism or a proton transfer mechanism based on this. In the present invention, a mixture with water is used, and therefore, it is considered that the terminal associated with carbon dioxide is a carboxylic acid. The proton is presumed to exhibit strong acidity by the above association mechanism. We have found that hydrazinoformic acid or substituted hydrazinoformic acid produced by reacting hydrazine hydrate or substituted hydrazine with carbon dioxide can be easily and safely decomposed into hydrazine hydrate or substituted hydrazine and carbon dioxide by heating to 40-70 ℃ to give hydrazine hydrate or substituted hydrazine as a product in high purity and high concentration at any concentration depending on the amount of water used. When it is necessary to carry out the distillation under conditions to obtain a low-concentration product, water is distilled off in a distillation column, and distillation is carried out in an azeotropic state with hydrazine hydrate to obtain 80% hydrazine hydrate, and further, only water is distilled off, and concentration and distillation are carried out to obtain 100% hydrazine hydrate. Further, purification was also performed at this time. The present invention has been completed by confirming these facts.

[ detailed description of solution for solving problems ]

In the present invention, after the ketoazine, hydrazone, substituted hydrazone, or schiff base compound represented by the following reaction formula (6) is subjected to hydrolysis reaction by stirring and mixing subcritical carbon dioxide, supercritical carbon dioxide, water necessary for liquid carbon dioxide and hydrate, and water in an amount equal to or greater than the amount of water necessary for hydrolysis at 40 ℃ or lower (not limited to this temperature), the subcritical carbon dioxide and supercritical carbon dioxide are in a state having both properties of gas and liquid, and are in a dispersed state of carbon dioxide-associated clusters. Therefore, after the reaction, the subcritical carbon dioxide and the supercritical carbon dioxide are changed to liquid phase conditions, and are combined with the liquid carbon dioxide to form a liquid phase. Upon standing, these carbon dioxide liquid and water layers were separated. The concentration of carbon dioxide dissolved in water and the amount of water dissolved in liquid carbon dioxide are shown in fig. 2. Supercritical carbon dioxide has the properties of an organic solvent and is therefore used as a solvent for extracting useful organic substances from natural substances. However, no report that liquid carbon dioxide exhibits organic solvent-like properties has been found in each of the documents. Although information on the phase equilibrium of supercritical carbon dioxide with low molar ratios of alcohol and organic solvent can be seen, the interpretation of detailed results on organic reactions is the first fact discovered in the present invention. In any of subcritical carbon dioxide, supercritical carbon dioxide and liquid carbon dioxide, the ketazine (ketoazine) as a raw material, the ketone formed by hydrolysis and the sparingly water-soluble substituted hydrazine formed are dissolved in a subcritical carbon dioxide layer, a supercritical carbon dioxide layer and a liquid carbon dioxide layer which may be microscopically referred to as a liquid state, and the ketone dissolved in water is also dissolved in these liquid carbon dioxide layers. Hydrazine hydrate, substituted hydrazine and amino compounds which are readily soluble in water are dissolved in water and thus in the aqueous layer.

As shown in the data (1), the specific gravity of liquid carbon dioxide differs depending on the temperature and the pressure at which it is liquefied. The critical point of the liquid carbon dioxide is 31.1 deg.C and 7.38 MPa. The density of the liquid carbon dioxide at each temperature and pressure is shown in data (1). The solvent used in the present invention is subcritical carbon dioxide, supercritical carbon dioxide, liquefied carbon dioxide and water, and after the reaction is completed, the temperature or/and pressure is adjusted to convert the subcritical carbon dioxide and the supercritical carbon dioxide into liquid carbon dioxide. As shown in fig. 2, both the water dissolved in the liquefied carbon dioxide at low temperature and the liquefied carbon dioxide dissolved in the water have very low concentrations. The immiscible water and liquefied carbon dioxide are in a separated state. Even if freezing point depression is shown by ketone azine or ketone hydrazone or ketone substituted hydrazone and hydrazine hydrate or substituted hydrazine, carbazic acid or substituted carbazic acid, etc., which are dissolved in water or liquefied carbon dioxide, ice is formed when water amount becomes large to reach very low temperature. The aqueous layer was solidified by stirring, and thus was in a slurry state in which the aqueous layer was solidified in the liquid carbon dioxide layer. When the specific gravity of the liquid carbon dioxide is 1 or less at-10 ℃ or higher, and the method of the present invention is carried out under preferable reaction conditions, the liquid carbon dioxide layer moves to the upper layer and the water layer moves to the lower layer because of the mixed system of the liquid carbon dioxide and water. When the above raw materials that can be dissolved in liquefied carbon dioxide and water are used, a state in which the raw materials are dispersed in liquefied carbon dioxide and water or 3 layers of liquefied carbon dioxide, water, and raw materials are formed. The raw materials and products cause freezing point depression, and the slurry of the water layer solidified in the liquid carbon dioxide layer may be treated, but from the viewpoint of reactivity, thermal efficiency, post-treatment, etc., the reaction is preferably carried out at a temperature of about-30 ℃ or higher and 40 ℃ or lower. It is further preferable to carry out the reaction at a temperature of-10 ℃ to 30 ℃. The pressure with respect to these temperatures depends on the volume of the pressure vessel and the filling amount (filling constant) of the filled liquid carbon dioxide, which will be explained in the items of fig. 4. The solidifying point of 60% hydrazine hydrate is-70.7 deg.C, and the solidifying point of 100% hydrazine hydrate is-51.7 deg.C. However, the reaction conditions are not limited to the above.

(non-patent document 4)

[ Table 1]

Any ratio of liquid carbon dioxide can be used relative to the amount of azine, hydrazone, substituted hydrazone, or schiff base compound of the starting material. As the hydrolysis reaction proceeds, the ketone azine, hydrazone, substituted hydrazone, or schiff base compound of the raw material is hydrolyzed to hydrazine hydrate, substituted hydrazine, carbazic acid, substituted carbazic acid, carbamic acid derivatives, amino compounds, and ketone or carbonyl compounds. The generated water-soluble hydrazine hydrate, substituted hydrazine, hydrazinoformic acid and substituted hydrazinoformic acid are dissolved in a water layer, and ketone, water-insoluble substituted hydrazines and substituted hydrazinoformic acid are dissolved in liquid carbon dioxide. The schiff base compound is decomposed into a carbonyl compound and an amino compound or a carbamic acid derivative, and is also dissolved in the liquid carbon dioxide layer or the aqueous layer.

The hydrolysis by this technique does not occur at all in the reaction of ketone with hydrazine hydrate, hydrazone, or substituted hydrazine to return to the azine, hydrazone, or substituted hydrazone, or by-products such as ketone condensates are not produced at all. After the reaction, the temperature or pressure is adjusted to be subcritical or supercritical carbon dioxide, and the carbon dioxide is converted into liquid carbon dioxide, and separated into a liquid carbon dioxide layer and a water layer. The remaining compound in the form of hydrazinoformic acid or substituted hydrazinoformic acid can be easily and safely decomposed into hydrazine hydrate or substituted hydrazine and carbon dioxide by heating the aqueous layer to 30 to 100 c, preferably 40 to 70 c (reaction formula 7). However, the condition is not limited thereto. The same applies to the schiff base compound.

The concentration of hydrazine hydrate or substituted hydrazine depends on the amount of water added, and hydrazine hydrate having a concentration close to the target concentration can be obtained directly by adding an amount of water corresponding to the target product concentration of hydrazine hydrate at the time of hydrolysis reaction. Hydrazine hydrate is generally used in concentrations of 60-100%. Some users sometimes also use 5-60% hydrazine hydrate, and the amount of water can be adjusted to achieve this concentration. When the concentration of the crude hydrazine hydrate is set to a precise product concentration, the concentration of the crude hydrazine hydrate obtained is analyzed, and a high concentration of hydrazine hydrate or water is added as necessary to adjust the concentration to a predetermined concentration.

Further, when high-purity hydrazine hydrate is required, it can be obtained by rectifying the obtained high-concentration hydrazine hydrate. When rectifying with 100% hydrazine hydrate, the product can be adjusted to any concentration by dilution to meet various concentrations of hydrazine hydrate. In addition, it can be used to adjust the concentration of crude hydrazine hydrate. In addition, when anhydrous hydrazine is required, it can be obtained by dehydrating 100% hydrazine hydrate and distilling it as necessary. Hydrazine hydrate is azeotropic with water at 80%, so when fractionating as an azeotropic product, 80% hydrazine hydrate is obtained, and if the amount of water used for the reaction is set to be equal to or less than the amount of water required for hydrolysis of azine or hydrazone and the amount necessary for formation of 80% hydrazine hydrate, hydrazine hydrate of any high concentration of 80% or more can be obtained. Since the substituted hydrazine does not form a hydrate, water in an amount larger than the amount required for hydrolysis may be added. Only water is distilled off from these by heating to the boiling point of water, and then the concentrated 100% hydrazine hydrate or substituted hydrazine is distilled off. In the distillation of hydrazine hydrate, it is necessary to perform distillation in an inert gas such as nitrogen gas in order to avoid decomposition of hydrazine hydrate and decomposition by oxygen in the air. Furthermore, substituted hydrazines are less stable and therefore require distillation in inert gases and additives suitable for substituted hydrazines.

[ reaction formula 6]

[ chemical formula 1]

Ketone azines

The compound (1) in the reaction formula (6) represents ketazine (ketoazine), and the compound (2) represents ketone. The compound (3) represents the same ketone as the compound (2) or another kind of ketone. The compound (4) represents hydrazine hydrate (hydrazine hydrate). R of chemical formula 1₁、R₂、R₃、R₄May be the same or different, respectively, or may be combined, or R may be₁And R₂And R₃、R₄Bonding may be possible. The carbon atom may contain a heteroatom such as a hydrogen atom, a nitrogen atom, an oxygen atom, or a sulfur atom. May have a substituent. The substituent may be an alkyl group, an alkynyl group, an alkenyl group, an aralkyl group, an alkylene group, an aryl group, an allyl group, a condensed ring group, a group having a hetero atom, or a substituent such as a halogen group, a nitro group, an OH group, or a mercapto group, which does not adversely affect the formation of a ketone azine or hydrazone. However, the substituents are not limited thereto. With the proviso that at least R is₁、R₂、R₃、R₄A structure in which 1 carbonyl group and hydrazine are bonded.

[ chemical formula 2]

Ketones (1)

A ketone having the condition represented by the formula (1). R₁、R₂The same as described in chemical formula (1).

[ chemical formula 3]

Ketones (2)

A ketone having the condition represented by the formula (1). R₃、R₄The same as described in chemical formula (1).

[ chemical formula 4]

Hydrazine hydrate (hydrazine hydrate)

H₂NNH₂·H₂O

[ chemical formula 5]

Hydrazone(s)

Hydrazone representing the condition shown in chemical formula (1). R₁、R₂、R₃、R₄The same as described in chemical formula (1). R₅、R₆Also with R of formula (1)₁、R₂、R₃、R₄The same applies to the contents described in (1).

[ chemical formula 6]

Hydrazinoformic acid (hydrazinoformic acid)

H₂NNH-COOH

[ chemical formula 7]

Substituted hydrazines

R in the formula (7)₅、R₆The same as described in chemical formula (5).

[ reaction formula 7]

Hydrolysis of hydrazinoformic acid (hydrazinoformic acid)

[ chemical formula 14]

H₂NNH-COOH+H₂O→H₂NNH₂·H₂O+CO₂

ADVANTAGEOUS EFFECTS OF INVENTION

The invention relates to a method which comprises the following steps: the ketone azine, hydrazone, or substituted hydrazone represented by the chemical formula (1) or (5) is hydrolyzed in subcritical carbon dioxide, supercritical carbon dioxide, and liquid carbon dioxide at low temperatures such as room temperature without using a proton catalyst such as an inorganic acid, etc., to obtain hydrazine hydrate or substituted hydrazine in high purity and at high concentration or at any concentration substantially without generating a by-product in a 1-stage reaction, and a liquid carbon dioxide layer (including a subcritical or supercritical state converted by changing temperature and pressure) and an aqueous layer are subjected to layer separation to produce hydrazine hydrate or substituted hydrazine by an easy and safe method in an inexpensive, energy-saving, and pollution-free manner without by-products. A process for producing hydrazine hydrate or substituted hydrazine, which is capable of easily separating, recovering and recycling hydrazine hydrate or substituted hydrazine without causing side reactions of liquid carbon dioxide to be used and a ketone or aldehyde to be used as a raw material.

The object of the present invention is to obtain hydrazine hydrate or substituted hydrazine, but it is understood from the above-mentioned presumed reaction mechanism that the reaction is not limited to hydrolysis of ketone azine or hydrazone, and the reaction can be used for hydrolysis of a compound having an imino bond (-C ═ N-) represented by a structure such as schiff base.

Drawings

FIG. 1 shows CO₂pH of saturated water.

FIG. 2 shows CO₂Solubility with respect to water and water with respect to CO₂The solubility of (a).

FIG. 3 shows CO₂A state diagram of (1).

FIG. 4 shows CO in a pressure vessel₂The state of (1).

Detailed Description

The present invention is described in detail below.

The present invention is a method for producing hydrazine hydrate or substituted hydrazine, which comprises adding a ketone azine, hydrazone or substituted hydrazone to a mixed system of subcritical carbon dioxide, supercritical carbon dioxide or liquid carbon dioxide and water, and stirring and mixing the mixture at-56.6 ℃ or higher and 60 ℃ or lower, preferably-30 ℃ to 40 ℃, and more preferably-10 ℃ to 30 ℃ to hydrolyze the ketone azine, hydrazone or substituted hydrazone, thereby converting the ketone, hydrazine hydrate or substituted hydrazine into a ketone and hydrazine hydrate or substituted hydrazine with high efficiency and high concentration. For a detailed description, refer to "detailed description section of solution to problem". It is considered that, when the detailed analysis of the reaction results is carried out, the reaction proceeds as shown in the reaction formulas (6) and (9). Further, if the reaction formula (6) is analyzed in detail, the reaction and the reaction product of the reaction formula (8) and the reaction formula (7) can be confirmed. After the hydrolysis reaction, the temperature and pressure of the subcritical carbon dioxide layer and the supercritical carbon dioxide layer are adjusted, and preferably, all of them are separated after forming a liquid carbon dioxide layer, and the raw material ketone can be confirmed by gas chromatography or liquid chromatography. If the liquid carbon dioxide is carbonated from the liquid carbon dioxide layer and gasified, the ketone remains. The separated aqueous layer is concentrated under reduced pressure at low temperature or a poor solvent such as methanol dissolved in water is added to precipitate a part of crystals. The crystals were confirmed by IR and liquid chromatography and identified as hydrazinoformic acid (hydrazinoformic acid) or substituted hydrazinoformic acid. Hydrazinoformic acid or substituted hydrazinoformic acid is an unstable compound and when heated to a temperature of about 40 ℃ to 60 ℃, it is easily, safely and completely decomposed into hydrazine hydrate or substituted hydrazine and carbon dioxide. When the aqueous layer of this reaction was heated, bubbles were generated, and it was found that carbon dioxide was generated by analysis.

[ hydrolysis in conventional Process for producing Acetonazine or Acetonhydrazone ]

In a conventional process for producing acetone azine, all of the components after the reaction, i.e., volatile substances such as ammonia, acetone azine, acetone hydrazone, hydrazine hydrate, water, etc., are distilled off once, and salts are concentrated at the bottom of a distillation column, separated and removed as an aqueous solution. At the same time, ammonia is recovered from the volatile constituents and then ketones are separated. An aqueous solution containing acetone azine and acetone hydrazone is introduced into a thermal decomposition reaction in a hydrolysis column.

With respect to R₁、R₂、R₃、R₄In order to hydrolyze methyl acetone azine, an aqueous acetone azine solution (acetone azine and water show azeotropy; hydrazine hydrate and water are also azeotropy) in the bottom tank of a multi-plate hydrolysis column is heated to 150 ℃ so that K1 shown in the reaction formula (1) slightly exceeds 130-phase K2, excess water is distilled off first, a very small amount of free acetone is distilled off to avoid recombination of hydrazine hydrate and acetone formed by high-temperature pyrohydrolysis, and the acetone formed by non-hydrolyzed recombination is cyclically pyrolyzed at high temperature, and acetone is distilled off from the top of the column little by little. The hydrazine hydrate formed remains at the bottom of the column. Acetone azine is circulated for a long time with a large amount of steam consumed to obtain a 20-30% aqueous solution of hydrazine hydrate. When acetone azine is exposed to high temperatures for a long period of time, by-products such as pyrazoline and acetone condensate formed from acetone hydrazone, one of which is hydrolyzed, increase. In order to avoid decomposition of 20 to 30% of low-concentration hydrazine hydrate obtained at the bottom of the column by oxygen in the air and to ensure safety, separate rectification is performed in the presence of an inert gas such as nitrogen, water is distilled off and concentrated first, and then rectification is performed as an azeotrope of hydrazine hydrate and water to obtain 80% hydrazine hydrate. Even so, it contains impurities. When hydrazine hydrate of high purity and high concentration is required, in order to prevent oxidation and to ensure safety, water is first distilled off in the presence of an additive gas such as nitrogen gas to increase the concentration, and rectification is performed again. In order to obtain 100% hydrazine hydrate, water is first distilled off from the column top in the presence of an inert gas such as nitrogen gas in order to prevent oxidation, 100% hydrazine hydrate is obtained at the column bottom, and the hydrazine hydrate is rectified again to obtain 100% hydrazine hydrate from the column top.

When a substituted hydrazine is obtained, it cannot be obtained by the same treatment as hydrazine hydrate since it is an unstable compound. Special environmental conditions for the distillation of the substituted hydrazine are required.

[ hydrolysis in the conventional Process for producing Hydrogen peroxide ]

Methyl ethyl ketone is used in the conventional hydrogen peroxide method. In the case of examples of the patent and chemical knowledge, the hydrogen peroxide method first requires the reaction of methyl ethyl ketone with ammonia to produce methyl ethyl ketimine. In the case of acetone, acetone is not used because the acetoneimine is unstable. As for the hydrogen peroxide method, the following are described in the patent: starting from the mixing of the starting methyl ethyl ketone and ammonia, methyl ethyl ketazine is formed as a result. Methyl ethyl ketazine is a relatively stable compound and is more difficult to hydrolyze, and although high-temperature pyrohydrolysis is performed, the reaction is also an equilibrium reaction shown in the reaction formula (5). The difference between the equilibrium constants K1 and K2 is very small during high-temperature thermal hydrolysis, so that the temperature of K2 exceeding the K1 constant is 180-200 ℃. A mixture of water necessary for the thermal hydrolysis of methyl ethyl ketone azine and water necessary for the hydrate of hydrazine in an amount equal to or larger than the theoretical amount is heated from the outside or high-temperature steam of 180 ℃ and 200 ℃ is blown into the mixture to heat the mixture, methyl ethyl ketone which is extremely little dissociated at a time is distilled off from the column of the hydrolysis column, and the produced aqueous hydrazine hydrate solution remains at the bottom of the column. A large amount of energy is consumed and the mixture of undecomposed methyl ethyl ketazine and methyl ethyl ketazine where methyl ethyl ketone and hydrazine hydrate are recombined is infinitely recycled for a long time to obtain hydrazine hydrate. The energy consumed by hydrolysis in this process is much greater than that consumed by hydrolysis of acetone azine. When methylethylketazine is exposed to such a high temperature for a long period of time, the formation of by-products (most of the components are pyrazolines and ketone condensates) increases, and coloring of the product is also a serious problem due to these reasons and the like. In addition, this process requires a catalyst called tetramethyldiarsene as a highly toxic arsenic derivative. The method for recovering the catalyst and the cost required therefor become problems.

Others having R₁、R₂、R₃、R₄、R₅、R₆The azine compounds and hydrazone compounds having a carbonyl group with a large molecular weight of (1) cannot be hydrolyzed by heating. It can only be cleaved by hydrolysis with strong acids. Although the use of benzophenone, cyclohexanone, etc. is also disclosed, the hydrolysis with strong acid such as sulfuric acid gives a sulfate of hydrazine, etc. Neutralization with alkaline substances for obtaining hydrazine hydrate, there is the generation of largeA problem of salt by-products in an amount (non-patent document 3).

[ description of the case of Hydrazone ]

Hydrazone as an incomplete reaction substance in an intermediate state where a stable ketazine is formed in the reaction system and a small amount of hydrazone as an incomplete reaction substance formed by recombination of ketone and hydrazine hydrate at the time of thermal hydrolysis were confirmed. On the other hand, in the reaction with substituted hydrazines, the starting materials are substituted amines and ammonia and are therefore obtained as one of the compounds in a mixture of various products. Substituted hydrazones derived from substituted amines have no free hydrazine groups and are therefore non-reducing and stable. Unlike the production method in which 2 molecules of ketone and 1 molecule of hydrazine hydrate are reacted to form ketazine and form a stable compound, only the incomplete reaction product when a mixture of ketone and ammonia is reacted with an oxidizing agent such as sodium hypochlorite to form hydrazine hydrate and the hydrazone formed by further binding 1 molecule of ketone to the produced hydrazine hydrate can be used, the method has the same problems as the production methods of the 1 st and 2 nd methods. The substituted hydrazone is not particularly advantageous because it has solubility in water in the subcritical state carbon dioxide, in the supercritical state carbon dioxide, or in the liquid carbon dioxide, but has low solubility in water or in the liquid carbon dioxide. Since the ketazine or substituted hydrazone produced in the original synthesis reaction may be included in the form of hydrazone or substituted hydrazone, it is considered that the conversion to hydrazine hydrate or substituted hydrazine upon thermal hydrolysis, or thermal hydrolysis under liquid carbon dioxide (including subcritical carbon dioxide and supercritical carbon dioxide systems) in the present invention, is small, but it is also considered that the object is achieved, that is, the target product is obtained. In addition, the hydrazone compound undergoes a disproportionation reaction to form an azine compound and a hydrazine. The generated hydrazine is decomposed by the oxidizing agent.

As an intermediate of the treatment of the present invention, the existence and the possibility of the course of the hydrazone compound are considered. When the reaction was confirmed by liquid chromatography in the intermediate stage, a peak presumed to be a hydrazone compound was confirmed. In addition, in the thermal hydrolysis, the presence of the hydrazone compound was also confirmed in the reaction liquid in the intermediate stage by liquid chromatography. Since the oxidizing agent is not present in the treatment reaction liquid of the present invention, the hydrazone compound is considered to be possibly present. It is considered that it is produced as a decomposition product during the thermal hydrolysis treatment, without being completely decomposed. When the treatment method of the present invention is applied after separating the stable hydrazone compound dissolved in water, the effect of the present invention, that is, the hydrazine hydrate can be obtained by hydrolysis in the same manner as the azine compound without generating a by-product.

[ case of Schiff base Compound ]

The azomethine bond of the Schiff base compound frequently used for stabilizing a carbonyl compound or an amino compound corresponds to a half structure of the ketoazine used in the present invention. In order to hydrolyze them to recover carbonyl compounds or amino compounds, the conventional treatment method of those skilled in the art is hydrolysis using inorganic acids. The same disadvantages and problems are associated with ketone azines. Having a half structure of ketone azine, it can be said that the hydrolysis reaction is equivalent to and the same as that of ketone azine. It is needless to say that the method of the present invention, i.e., hydrolysis using subcritical, supercritical or liquid carbon dioxide is effective as a means for solving the problem.

[ solubility between carbon dioxide and water ]

It is desirable that carbonic acid exhibits the effect of acid hydrolysis, however, in carbonated water, the Pk of carbonic acid₁＝3.60、Pk₂When 10.25, Pk of carbonic acid is 6.35, it is a very weak acid and does not exhibit the function of an acid catalyst for promoting hydrolysis. The lower the temperature and the higher the pressure of carbon dioxide, the more the solubility in water increases and the lower the pH of the aqueous solution becomes (fig. 1).

However, carbonic acid at this pH level does not preferentially cause hydrolysis of the ketazine or hydrazone or substituted hydrazone. The hydrolysis of ketazine is less, and the acidity of carbonic acid rather catalyzes the formation of more by-products. The solubility of carbon dioxide relative to water is shown in figure 2. The amount of water dissolved in carbon dioxide is high at a high temperature and a high pressure in a supercritical state, but since the temperature is high, side reactions preferentially occur, and hydrazine hydrate or substituted hydrazine cannot be obtained. Although the solubility of water in low-temperature liquid carbon dioxide is low, the water dissolved is important. Sufficient stirring is required to increase the dissolution of new water and increase the probability of contact with liquid carbon dioxide.

[ behavior and solubility of carbon dioxide (gas, subcritical, supercritical, liquid) ]

The state diagram of carbon dioxide is shown in fig. 3. In the presence of water, even when the hydrolysis of ketazine was carried out in the subcritical and supercritical carbon dioxide states at higher temperatures and higher pressures, such as the central region of each region of the phase diagram, no good hydrolysis of ketazine was confirmed. Instead, the acidic catalytic effect of carbonic acid catalyzes the formation of a large number of by-products. This problem does not exist in the liquid carbon dioxide phase.

When the hydrolysis of ketazine or hydrazone or substituted hydrazone is carried out in the presence of water under the condition that the state diagram of carbon dioxide is in the state of liquid carbon dioxide or supercritical carbon dioxide, the aqueous layer is separated, and hydrazinoformic acid or substituted hydrazinoformic acid other than hydrazine hydrate or substituted hydrazine that is present is subjected to heating and heating treatment to hydrolyze the hydrazine hydrate or substituted hydrazine, high-concentration hydrazine hydrate or substituted hydrazine is obtained in the same manner with extremely high yield and high efficiency, and the formation of pyrazoline or ketone condensate that is easily formed when the reaction is carried out in the state of high-concentration carbonated water under high-pressure, subcritical carbon dioxide under high-temperature conditions, or supercritical carbon dioxide is completely absent. When subcritical carbon dioxide and supercritical carbon dioxide are used, since raising the temperature shows a bad result, a good hydrolysis effect is shown when the treatment is performed at a temperature as low as possible near the critical point.

[ case in pressure vessel ]

When air is present in the pressure reaction vessel, the air is expelled with carbon dioxide and replaced with carbon dioxide, and the volume of the pressure reaction vessel needs to be as follows: there is a margin for the reaction operation with respect to a filling constant above the capacity of the liquid carbon dioxide to be filled, the ketazine or hydrazone or substituted hydrazone of the raw material and water. The gas layer is almost occupied by carbon dioxide. The pressure inside is considered to be similar to the pressure vessel internal state diagram when only liquid carbon dioxide is filled. The temperature change and pressure change within the pressure vessel depend on the filling constant of the liquid carbon dioxide, and below the critical temperature, the liquid carbon dioxide and the gasified carbon dioxide are in equilibrium in the phase diagram of fig. 3, lying on the boiling point line. In accordance with the filling constant, when the temperature in the pressure vessel rises, the liquid carbon dioxide in the pressure vessel is in a full state at the respective corresponding temperatures, and if the temperature further rises, the pressure rises sharply to be in a supercritical state as shown in fig. 4.

The black line indicates that full fill is reached at about 22 ℃ at a fill constant of 1.34, showing the liquid and pressure change in the supercritical state as the temperature is further increased. The grey line indicates the attainment of full fill at 29 ℃ at a fill constant of 1.6, showing the pressure change in the supercritical state at further temperature rise. The liquid carbon dioxide and the gaseous carbon dioxide are in an equilibrium state and are in a state on the boiling line.

[ hydrolysis reaction of azines with liquid Carbonic acid, detailed description of the operation ]

The azine, hydrazone, or substituted hydrazone to be used as the raw material may be a compound which is liquid when the raw material is charged by an appropriate method, or a solid compound which is solid when the reaction pressure vessel is opened and charged in a necessary amount. As described above, the air in the reaction vessel is completely replaced with carbon dioxide before the liquid carbon dioxide is filled. The solid raw material gradually dissolves as the reaction proceeds even if it is not completely dissolved in the liquid carbon dioxide.

In the case of a hydrazone obtained by partially hydrolyzing an azine by adding 3 moles or more of water to 1 mole of the azine in subcritical carbon dioxide, supercritical carbon dioxide, or liquid carbon dioxide, the amount of the liquid carbon dioxide to be added to the azine or hydrazone is not particularly limited, and is preferably in a large excess amount with respect to 1 mole of the hydrazone by adding 2 moles or more of water. The amount of water is not particularly limited, and may be an amount of water adjusted to a target concentration of hydrazine hydrate or substituted hydrazine, although the amount of water is 3 moles or more relative to 1 mole of azine and 2 moles or more relative to 1 mole of hydrazone, and in the case of substituted hydrazone, 2 moles or more of water is necessary relative to 1 mole of substituted hydrazone.

Regarding the reaction conditions, the temperature of the liquid in the state diagram of carbon dioxide shown in FIG. 3 is-56.6 ℃ to 31.1 ℃, the pressure is 0.52MPa or more to 7.38MPa or more, desirably-20 ℃ to 31 ℃, the pressure is 2.0MPa or more to 7.4MPa or more, and more preferably-10 ℃ to 20 ℃ and 2.8MPa or more to 5.8MPa or more, and the pressure at these temperatures is on the boiling line of the state diagram of liquefied carbon dioxide and depends on the filling constant, and when the pressure vessel is filled at a high temperature side, a slight change in temperature may cause a sharp pressure rise. Therefore, in order to select a filling constant of the liquid carbon dioxide in the pressure reaction vessel and to cope with a pressure rise, the pressure resistance may have a margin of, for example, 10 MPa. It is important to install a safety valve in advance which releases the pressure to the outside of the system when higher pressure is reached. However, the pressure resistance of the pressure vessel is not limited thereto. In the case of carbon dioxide in a supercritical state in a subcritical carbon dioxide state and at a temperature of 31.1 ℃ or higher and a pressure of 7.38MPa or higher, a temperature of 31.1 ℃ to 80 ℃ or lower and a pressure of 7.38MPa or higher at a corresponding filling constant are preferred. The pressure resistance of the pressure vessel is the same as that of liquid carbon dioxide. The container and method of use of liquid carbon dioxide is described with reference to high pressure gas management and manufacturer's instructions. After hydrolysis of azine was carried out at a temperature and a pressure at which supercritical carbon dioxide and liquid carbon dioxide are present, all carbon dioxide including supercritical carbon dioxide was converted into a liquid carbon dioxide layer by changing the temperature, and 2 layers of a liquid carbon dioxide layer and a water layer were formed and separated. While maintaining the low temperature, hydrazine hydrate and hydrazinoformic acid are present in the aqueous layer. When the temperature is raised to above 30 ℃, the hydrazinoformic acid generates carbon dioxide, and hydrazine hydrate is formed. The safe decomposition temperature of the carbazic acid is preferably 40-60 ℃. In the case of subcritical carbon dioxide and in the case of supercritical carbon dioxide, the influence of temperature is very large, and low temperature is desired for the purpose of hydrolysis, so that it is desirable to select conditions of 31.1 ℃ and 7.38MPa close to the critical point. However, the temperature and pressure are not limited to these values and conditions, and may be those suitable for the operation and the operation.

Commonly commercially available siphoned liquefied carbon dioxide storage bottles are sold in a boiling liquid state. In large-scale, large-scale use, it is sold as liquefied carbon dioxide at a low temperature of-20 ℃ in a flask-type container having a vacuum heat insulating layer, and since the heat transfer is not zero, the low temperature is maintained by the evaporation of the internal liquid carbon dioxide.

Regarding the separation of the liquid carbon dioxide layer and the water layer, the inversion of the layers occurs depending on the temperature and the concentration of the respective dissolved substances, and therefore cannot be uniformly shown. The separation was performed as measured with a level gauge with a sensor. The solubility of the free ketone varies depending on the kind of ketone, but the amount of the ketone dissolved in the liquid carbon dioxide layer is large. Although the amount of acetone or methyl ethyl ketone used in the present production varies depending on the kind of ketone, acetone or methyl ethyl ketone generally used in the present production is easily dissolved in liquid carbon dioxide, and particularly methyl ethyl ketone is insoluble in water. In the case of using a large amount of liquid carbon dioxide relative to azine or substituted hydrazone, the liquid carbon dioxide in which these ketones are dissolved can be recycled in a state in which these ketones are dissolved. In the case of the reaction of subcritical carbon dioxide or supercritical carbon dioxide with the aqueous layer, the aqueous layer is separated. However, the present invention is not limited to this method.

When the dissolution of the ketone in the liquid carbon dioxide becomes slow or difficult, the subcritical carbon dioxide, the supercritical carbon dioxide, and the liquid carbon dioxide are gasified by a gasifier and released to the outside of the system, and the ketone remains as a residual liquid. The recovered ketone can be directly recycled, and can be rectified and purified when purification is needed. The operation may be arbitrarily selected according to the operation and operation.

If it is desired to effectively utilize the heat energy in the entire reaction system, when the liquid carbon dioxide is gasified in the gasifier, cooling is performed by the heat of gasification, and the cold heat is recovered as low-temperature brine while being warmed with brine or the like, and used for cooling liquefaction in distillation of ketone or for other cooling sections. The gasified carbon dioxide is cooled by the cooling heat at the time of gasification or cooled and liquefied by cooling the carbon dioxide when there is another cold source in the vicinity, and then pressurized and liquefied by a compressor. When carbon dioxide is cooled in advance, the efficiency of the compressor for compression and liquefaction can be improved, and the electric energy used by the compressor can be suppressed. The compression by the compressor releases heat, and the heat is released to the outside. The heat generated at this time is recovered and utilized as heating energy for the concentration and purification of hydrazine hydrate or the distillation of ketone. It is suggested that energy consumption is ideally suppressed by applying these effective energies (energy). However, it is not limited to these operations.

R shown in (1)₁、R₂、R₃、R₄、R₅、R₆The same substituents are shown in each compound. R₁、R₂、R₃、R₄、R₅、R₆The groups may be the same, partially different, or all different. May also be R₁、R₂And R₃、R₄And a ring structure formed by bonding. If recycling is considered, it is desirable that the compound of formula (2) and the compound of formula (3) are the same compound. R₁、R₂、R₃、R₄、R₅、R₆Represents: hydrogen; an alkyl group, an alkenyl group, an alkynyl group, an alkylene group, an aralkyl group, an alkenylene group, an arylene group, an alicyclic group, an aryl group, an allyl group, a heterocyclic group, a condensed ring group, a diradical of these and the like which may form a branched chain, may have a substituent which does not react with ammonia, carbon dioxide, hydrazine and the like, and may have a hetero atom. However, it is not limited to these.

As R₁、R₂、R₃、R₄、R₅、R₆Specific examples of (4) include alkyl groups such as hydrogen, methyl, ethyl, isopropyl, and isobutyl. Cyclic alkyl groups such as cyclopentyl and cyclohexyl are shown. Cyclic alkyl groups such as cyclopentyl and cyclohexyl including carbon atoms in the compound structural formula are shown. Vinyl, allyl, and like alkenyl groups are shown. Cyclopentenyl, cyclohexenyl, and like cycloalkenyl groups are shown. The cycloalkenyl group including the carbon of the structural formula of the compound, such as cyclopentenyl group, cyclohexenyl group, etc., is shown. An aromatic ring group such as phenyl or naphthyl is shown. Shows pyrazolyl, pyrazolinyl, imidazolyl, imidazolinyl, pyridyl, pyrrolyl, triazolyl, oxazolylAnd heterocyclic groups such as pyrazinyl and quinolyl. These groups may have a substituent such as an alkoxy group, a halogen group, a nitro group, an amino group, an aryloxy group, an aromatic ring group, or a heterocyclic group, which is not reactive with ammonia, carbon dioxide, hydrazine, or the like. Preferred are hydrogen, methyl, ethyl, isobutyl, aryl, cycloheptane ring, cyclohexane ring and the like. Specifically, the compounds represented by the chemical formulas (2) and (3) include aldehydes such as acetaldehyde, isopropionaldehyde, benzaldehyde, naphthaldehyde, and furfural, and acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl cyclopentyl ketone, cyclopentanone, cyclohexanone, furanone, acetophenone, benzophenone, anthraquinone, naphthoquinone, fluorenone, and fluorenylketone (fluoroenyl ketone). However, it is not limited to these.

Examples

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

[ method of analyzing and quantifying hydrazine hydrate ]

Method for analyzing hydrazine hydrate obtained in the following examples.

The analysis of hydrazine hydrate can be carried out by gas chromatography, preferably by titration for accurate analysis.

[ hydrazine hydrate analysis method by titration ]

Reagent

1) Hydrochloric acid (3+2)

To 300ml of white hydrochloric acid was added 200ml of deionized water.

2) Chloroform (reagent special grade)

3) M/40 Potassium iodate solution (5.35g KIO)₃/l)

After heating potassium iodate (standard reagent for volumetric analysis) at 130 ℃ for 2 hours, it was left to cool in a desiccator, and the amount corrected to 10.701g was measured to the extent of 0.1mg, and transferred to a 2000ml volumetric flask, and dissolved in deionized water to a constant volume { prepared in such a manner that the factor (F) reached 1.000 }.

Operation of

1) Accurately weighing the sample collection amount (delta) corresponding to the concentration, putting the sample collection amount into a 500ml volumetric flask, and fixing the volume by using deionized water.

2) Exactly 10ml of the solution was taken out, transferred to a stoppered flask (capacity 300ml), and 50ml of hydrochloric acid (3+2) was added.

3) Titrating with M/40 potassium iodate solution, adding 5ml of chloroform when the end point is approached, shaking vigorously, titrating until the red color of the chloroform layer disappears, and repeating shaking vigorously.

The content was determined by the following equation.

[ number 1]

M/40 potassium iodate 1 ═ 0.0012515g N2H 4. H2O

Remarks for note

[ Table 2]

(. about.) sample volume corresponding to concentration was as described above.

[ Synthesis of Standard test materials ]

[ Synthesis of Acetonazine ]

100g (2 moles) of 100% hydrazine hydrate was added to 2,320g (40 moles) of acetone at room temperature. At this time, the temperature rises due to the heat of reaction. Then stirring the mixture for 2 hours at an internal temperature of 40 to 50 ℃. After the reaction, the reaction mixture was cooled to room temperature, 828g (6 mol) of anhydrous potassium carbonate was slowly added thereto under vigorous stirring, and the mixture was stirred at room temperature for 2 hours to remove by-produced water. In this case, if the stirring is insufficient, the potassium carbonate may be solidified, and it is necessary to pay attention.

After drying, the potassium carbonate was filtered off, and the filtered potassium carbonate was washed thoroughly with acetone. After distilling off the remaining acetone under reduced pressure, the rectification of acetone azine was carried out by distillation under reduced pressure.

[ Synthesis of methyl Ethyl Ketone azine ]

100g (2 moles) of 100% hydrazine hydrate was added dropwise to 1,440g (20 moles) of methyl ethyl ketone with vigorous stirring while heating at 60 ℃. Heating was carried out from the outside during the dropwise addition so that 80 ℃ was reached at the end of the dropwise addition. Methyl ethyl ketone does not readily react with hydrazine hydrate. After the end of the dropwise addition, the reaction was carried out at 80 ℃ for 10 hours under vigorous stirring. Methyl ethyl ketone and 100% hydrazine hydrate are immiscible and thus form 2 layers. The upper methyl ethyl ketone layer was separated, dehydrated over anhydrous sodium sulfate, and dried. After sodium sulfate was filtered off, the remaining methyl ethyl ketone was distilled off under reduced pressure, and rectification of methyl ethyl ketone azine was carried out by distillation under reduced pressure.

Example 1

An autoclave having a capacity of 400ml and a pressure resistance of 20MPa and equipped with a safety valve and a stirrer was equipped with a liquefied carbon dioxide storage bottle with a siphon, a supercooling device, and a high-pressure constant pump, and the autoclave was immersed in a constant temperature bath. Carbon dioxide was introduced into the autoclave in advance to completely displace the air in the autoclave. The autoclave was set to 20 ℃ as a whole in a thermostatic bath at 20 ℃. A solution prepared by dissolving acetone azine 28g (0.25 mol) in water 31.5g (1.75 mol) was adjusted to 20 ℃ and then charged into an autoclave. On this basis, 213g (4.84 moles) of carbon dioxide from a liquid carbon dioxide storage bottle was slowly injected into the autoclave through the subcooler by a high-pressure fluid constant pump under stirring so as not to turn into gas at a time when liquefied carbon dioxide was introduced. The amount of the liquid carbon dioxide injected was determined from both the amount from the fixed displacement pump and the weight change of the autoclave after filling with the liquid carbon dioxide. The pressure in the autoclave showed about 5.7 MPa. At this point the valve was closed and the mixture was stirred at 20 ℃ for 12 hours. The liquid carbon dioxide and water and acetone azine contained in the reservoir contained about 270ml in liquid composition and about 130ml in gaseous state, which was on the boiling line of the state diagram.

After the reaction, since the specific gravity of liquid carbon dioxide at 20 ℃ is lower than that of water, the lower water layer portion was taken out to a pressure resistant vessel, dissolved carbon dioxide was released from a gas release valve, and then slowly heated to 55 ℃. The hydrazinoformic acid present in the water layer is decomposed into hydrazine hydrate and carbon dioxide, which is discharged out of the system from the release valve. The aqueous layer was sampled and the amount of hydrazine hydrate was calculated by the above titration analysis. From the results of the titration analysis, the hydrazine hydrate was found to be 11.75g (0.235 mol) (yield 94%). Regarding the concentration of hydrazine hydrate, since the amount of water dissolved in liquefied carbon dioxide at this temperature and pressure is very small, it is a hydrazine hydrate solution of about 38.4% concentration.

Example 2

The reaction and treatment were carried out in the same manner as in example 1 except that the temperature was 10 ℃ and water was 22.5g (1.25 mol). When the aqueous layer was analyzed by titration, hydrazine hydrate was calculated as 0.24 mol. The yield thereof was found to be 96%. It is an approximately 55.7% strength hydrazine hydrate solution.

Example 3

The reaction and treatment were carried out in the same manner as in example 1 except that the temperature was 0 ℃ and water was 22.5g (1.25 mol). When the aqueous layer was analyzed by titration, 0.246 mol of hydrazine hydrate was calculated. The yield thereof was found to be 98.4%. It is an approximately 57.2% strength solution of hydrazine hydrate.

Example 4

An autoclave having a capacity of 400ml and a pressure resistance of 20MPa and equipped with a stirrer, a liquefied carbon dioxide storage bottle with a siphon tube, a carbon dioxide storage tank, a subcooler, and a high-pressure constant-rate pump was placed on the upper part of the autoclave, and the autoclave was immersed in a constant-temperature bath. Carbon dioxide was introduced into the autoclave in advance to completely displace the air in the autoclave. The autoclave was brought to 32 ℃ as a whole in a thermostatic bath at 32 ℃. A solution prepared by dissolving acetone azine 28g (0.25 mol) in water 22.5g (1.25 mol) was adjusted to 32 ℃ and then charged into an autoclave. On this basis 219g (4.98 moles) of liquid carbon dioxide from a liquid carbon dioxide reservoir bottle passed through the subcooler was slowly injected into the autoclave with a high pressure fluid dosing pump under stirring. The internal pressure of the autoclave was about 9 MPa. If it is assumed that the liquid components are all liquid carbon dioxide, the filling constant of carbon dioxide corresponds to about 1.6, and since about 50g of the liquid components other than liquid carbon dioxide are filled, it cannot be said that the filling constant is exactly 1.6. At this point the valve was closed and the mixture was stirred at 32 ℃ for 12 hours. The pressure in the autoclave was about 9MPa at 32 ℃. In a bottle intended to be used as liquid carbon dioxide, the liquid carbon dioxide in the bottle is usually at a critical point of 31.1 ℃ or lower and is on the boiling line of the state diagram. Under the condition of the filling constant, the carbon dioxide storage bottle is in a critical carbon dioxide state of no gas layer and full of liquid at about 29 ℃. Since the pressure in the reaction autoclave rapidly increases even with a slight temperature change, a 200MPa autoclave equipped with a safety valve is used for maintaining the supercritical carbon dioxide layer for safety.

After the reaction was completed, the autoclave and the contents were cooled to 10 ℃, the water layer portion of the lower layer having a large specific gravity was taken out into a pressure resistant vessel, dissolved carbon dioxide was released from a gas release valve, and then slowly heated to 55 ℃. The hydrazinoformic acid present in the water layer is decomposed into hydrazine hydrate and carbon dioxide, which is discharged out of the system from the release valve. The aqueous layer was sampled and the amount of hydrazine hydrate was calculated by the above titration analysis. From the results of the titration analysis, hydrazine hydrate was 0.205 mol (yield: 82%). Regarding the concentration of hydrazine hydrate, since the amount of water dissolved in liquefied carbon dioxide at this temperature and pressure is very small, it is a hydrazine hydrate solution of about 47.3% concentration.

Example 5

An autoclave having a capacity of 400ml and a pressure resistance of 20MPa and equipped with a stirrer, a liquefied carbon dioxide storage bottle with a siphon tube, a vaporizer, a carbon dioxide storage tank, a subcooler, and a high-pressure constant-rate pump was placed on the upper part of the autoclave, and the autoclave was immersed in a constant-temperature bath. Carbon dioxide was introduced into the autoclave to completely displace the air in the autoclave. The autoclave was set to 20 ℃ as a whole in a thermostatic bath at 20 ℃. A solution prepared by dissolving 22.5g (1.25 mol) of methylethylketone azine in 35g (0.25 mol) of water was adjusted to 20 ℃ and then charged into an autoclave. On this basis 215g (4.9 moles) of liquid carbon dioxide passing through the subcooler was slowly injected into the autoclave with a high pressure fluid dosing pump under stirring. The valve was closed and the mixture was stirred at 20 ℃ for 12 hours. The filling constant of liquid carbon dioxide is about 1.6. At this fill constant, in a typical liquid carbon dioxide storage bottle, there are layers of liquid carbon dioxide and gaseous carbon dioxide within the bottle. At 29 ℃ or lower, the state is at equilibrium and on the boiling line of the state diagram. The pressure in the autoclave at 20 ℃ showed about 5.9 MPa.

Even at temperatures above this temperature, the temperature was on the boiling line of the state diagram up to 29 ℃. In order to ensure safety even when the temperature in the reaction autoclave is slightly changed, a 200-pressure autoclave equipped with a safety valve for maintaining a supercritical carbon dioxide layer was used.

After the reaction, the specific gravity of liquid carbon dioxide was lower than that of water at 20 ℃, and therefore the lower water layer portion was taken out to a pressure resistant vessel, and dissolved carbon dioxide was released from a gas release valve, followed by slowly heating to 55 ℃. The hydrazinoformic acid present in the water layer is decomposed into hydrazine hydrate and carbon dioxide, which is discharged out of the system from the release valve. The aqueous layer was sampled and the amount of hydrazine hydrate was calculated by the above titration analysis. From the results of the titration analysis, hydrazine hydrate was 0.233 mol (yield 93%). Regarding the concentration of hydrazine hydrate, the amount of water dissolved in liquefied carbon dioxide at this temperature and pressure is very small, and therefore, it is a hydrazine hydrate solution of about 54.0% concentration.

Example 6

As the raw materials, 72g (0.20 mol) of benzophenone azine, 188g (4.27 mol) of liquid carbon dioxide and 31.5g (1.75 mol) of water were used, and the filling constant was about 1.58. The same treatment as in example 1 was carried out to obtain 9.1g (0.182 mol) of hydrazine hydrate. The yield was 91% and the hydrazine hydrate concentration was 29.8%.

Example 7

The weight of the first empty autoclave and the weight of acetone presumably dissolved in liquid carbon dioxide by hydrolysis were subtracted from the measurement result of the weight of the autoclave charged with separated and stored liquid carbon dioxide in example 1, and the amount of residual liquid carbon dioxide was estimated to be 203 g. Then, 27g (1.5 mol) of water and 28g (0.25 mol) of acetone azine were charged, and the reaction and treatment were carried out in the same manner as in example 1. The fill constant is close to about 1.7. As a result of the analysis, it was found that the yield of hydrazine hydrate (10.4 g, 0.208 mol) was 83%.

Claims

1. A process for producing a hydrazine hydrate, a substituted hydrazine or an amino compound, characterized by hydrolyzing a ketone azine or hydrazone in the presence of carbon dioxide in a subcritical, supercritical or liquid carbon dioxide state to obtain a ketone and a hydrazine hydrate or a substituted hydrazine, or a hydrazinoformic acid or a substituted hydrazinoformic acid, or hydrolyzing a Schiff base compound to obtain a ketone, a carbonyl compound and an amino compound, or a carbamic acid compound or a substituted carbamic acid,

the production method is a production method under the following conditions:

the temperature, pressure and filling factor are combined under the conditions that the temperature of the carbon dioxide is below 60 ℃ and above-56.6 ℃ and the pressure of the carbon dioxide is above 0.52MPa to form the states of subcritical carbon dioxide, supercritical carbon dioxide and liquid carbon dioxide.

2. A method for producing a hydrazine hydrate, a substituted hydrazine or an amino compound according to claim 1, which is a method for producing a hydrazine hydrate, a substituted hydrazine or an amino compound under the following conditions:

the temperature, pressure and filling factor of the carbon dioxide are combined under the conditions that the temperature of the carbon dioxide is-30-40 ℃ and the lower limit range of the pressure of the carbon dioxide is 1.4-7.38 MPa to form subcritical, supercritical and liquid carbon dioxide.

3. The method for producing a hydrazine hydrate, a substituted hydrazine or an amino compound according to claim 1 or 2, wherein,

the carbon dioxide can be reused.

4. The method for producing a hydrazine hydrate, a substituted hydrazine or an amino compound according to claim 1 or 2, further comprising the steps of:

heating the hydrazinoformic acid or substituted hydrazinoformic acid to decompose the hydrazinehydrate or substituted hydrazine and carbon dioxide.

5. The method for producing a hydrazine hydrate, a substituted hydrazine or an amino compound according to claim 1 or 2, wherein,

the ketone azine is a compound represented by the chemical formula (1):

in the formula (I), the compound is shown in the specification,

R¹～R⁴each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, an aromatic cyclic group or a heterocyclic group, and these groups may be substituted with 1 or more substituents selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, a halogen group, an alkoxy group, an amino group, a nitro group, a mercapto group, an aryloxy group, an aromatic cyclic group and a heterocyclic group, as the case may be, or

R¹And R²Form a ring structure together with the carbon atom to which they are bonded, and here, the ring structure group may be substituted with a substituent selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, a halogen group, an alkoxy group, an amino group, a nitro group, a mercapto group, an aryloxy group, an aromatic ring group and a heterocyclic group as a substituent, or

R³And R⁴Together with the carbon atom to which they are bonded, form a ring structure, and here, the ring structure group may be substituted with a substituent selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, a halogen group, an alkoxy group, an amino group, a nitro group, a mercapto group, an aryloxy group, an aromatic ring group, and a heterocyclic group as a substituent, as the case may be.

6. The method for producing a hydrazine hydrate, a substituted hydrazine or an amino compound according to claim 1 or 2, wherein,

the hydrazone is a compound represented by the chemical formula (7):

in the formula (I), the compound is shown in the specification,

R¹、R²、R⁵、R⁶each independently is a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, an aromatic cyclic group or a heterocyclic group, and these groups may be selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, a halogen group, an alkoxy group, an amino group, a nitro group, a mercapto group, an aryloxy group, an aromatic cyclic group and a heterocyclic group as the case may beSubstituted with 1 or more substituents of the group, or

R¹And R²Together with the carbon atom to which they are bonded, form a ring structure, where the ring structure group may be substituted with a substituent selected from the group consisting of alkyl, alkenyl, alkynyl, halogen, alkoxy, amino, nitro, mercapto, aryloxy, aromatic ring group and heterocyclic group as a substituent, or

R⁵And R⁶Together with the nitrogen atom to which they are bonded, form a ring structure, and here, the ring structure group may be substituted with a substituent selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, a halogen group, an alkoxy group, an amino group, a nitro group, a mercapto group, an aryloxy group, an aromatic ring group, and a heterocyclic group as a substituent, as the case may be.

7. The method for producing a hydrazine hydrate, a substituted hydrazine or an amino compound according to claim 1 or 2, wherein,

the Schiff base is a compound shown in a chemical formula (9):

in the formula (I), the compound is shown in the specification,

R¹、R²、R⁷each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, an aromatic cyclic group or a heterocyclic group, and these groups may be substituted with 1 or more substituents selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, a halogen group, an alkoxy group, an amino group, a nitro group, a mercapto group, an aryloxy group, an aromatic cyclic group and a heterocyclic group, as the case may be, or

R¹And R²Together with the carbon atom to which they are bonded, form a ring structure, and here, the ring structure group may be substituted with a substituent selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, a halogen group, an alkoxy group, an amino group, a nitro group, a mercapto group, an aryloxy group, an aromatic ring group, and a heterocyclic group as a substituent, as the case may be.