JPH0227980B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing diethylenetriamine by ammonolysis of diethanolamine. More specifically, the present invention relates to a method for producing diethylenetriamine by reacting diethanolamine and ammonia in a liquid phase in an excess of ammonia in the presence of a phosphoric acid compound or a phosphorous acid compound. Diethylenetriamine is used as a paper strength agent, polyamide resin raw material, epoxy resin curing agent, chelating agent,
It is a useful chemical product that has a wide range of uses such as anticorrosive agents and surfactants. Such diethylenetriamine is industrially produced as a by-product of ethylenediamine production through the reaction of 1,2-dichloroethane and ammonia.
It is also obtained as a by-product of the production of ethylenediamine by the reaction of monoethanolamine and ammonia. In such a method, in the former case, a large amount of common salt equivalent to twice the mole of ethylenediamine is produced as a by-product, and since vinyl chloride monomer is mixed in, a large amount of processing cost is required when disposing of the waste liquid. Furthermore,
There are drawbacks such as significant corrosion of the equipment by chlorine ions. Furthermore, in either case, the production amount of diethylenetriamine is affected by the market conditions of ethylenediamine, which is a drawback. In addition, as a method for producing diethylenetriamine, there is a method in which monoethanolamine and ethylenediamine are catalytically reacted using a phosphorus-containing compound such as phosphoric acid as a catalyst (Japanese Patent Application Laid-Open No. 147600/1983).
A method of reacting monoethanolamine or ethylene glycol with ethylenediamine in the liquid phase using an inorganic compound mainly composed of alumina or silica as a catalyst (Japanese Patent Application Laid-Open No. 55-38329)
etc. These methods are still unsatisfactory because ethylenediamine is relatively expensive, the conversion rate of ethylenediamine is low, and the selectivity of diethylenetriamine is low. Taking these circumstances into consideration, the present inventors have conducted extensive studies on the reaction between diethanolamine and ammonia, and have found that under selected reaction conditions, the reaction between diethanolamine and ammonia is extremely high in the presence of a phosphoric acid compound or a phosphorous acid compound. We discovered that diethylenetriamine is produced and arrived at the present invention. That is, the present invention uses a phosphoric acid compound or a phosphorous acid compound as a catalyst, and diethanolamine and ammonia in a molar ratio of 1:5 to 1:35 under sufficient pressure to maintain the reactants in the liquid phase. This is a method for producing diethylenetriamine through a reaction. In this method, particularly favorable results are obtained when the reaction temperature is 260-290°C and the reaction system contains 5-40% by weight of water. According to the method of the present invention, diethylenetriamine can be produced with high selectivity by ammonolyzing diethanolamine in a liquid phase. Conventionally, when dialkanolamine and ammonia are reacted under high temperature and high pressure conditions, many cyclic amine compounds, mainly piperazine compounds, are produced (Japanese Patent Application Laid-open No. 149290/1983), and diethylenetriamine is hardly produced. It was only known. Furthermore, according to the method of the present invention, there is a large difference between the boiling point of the product diethylenetriamine (208°C) and the raw material diethanolamine boiling point (278°C).
The separation becomes easy and can be performed by a simple operation. Therefore, it can be easily separated by conventional separation operations such as flashing, stripping or distillation, and the remaining unreacted diethanolamine can be recovered and used as is. In other words, the method of the present invention for producing diethylenetriamine from diethanolamine yields the desired product in good yield, is easy to separate, and does not require a catalyst separation operation, so it is very easy to carry out industrially. be advantageous to In the method of the present invention, a phosphoric acid compound or a phosphorous acid compound is used as a catalyst. Phosphoric acid compounds include phosphoric acid, polyphosphoric acid, periodic table Ia
phosphates, phosphoric acid esters, ammonium phosphate, manganese phosphate, and phosphorous acid compounds. Phosphoric acid, Periodic Table Ia
phosphites, phosphite esters, and ammonium phosphites with metal atoms of groups Ib, a, b, and group metals. Specifically, ammonium hydrogen phosphite, phosphorous acid, ammonium phosphite, potassium hydrogen phosphite, sodium hydrogen phosphite, copper phosphite, silver phosphite, magnesium phosphite, calcium phosphite, Zinc phosphite, cobalt phosphite, nickel phosphite, ammonium hydrogen phosphate, sodium hydrogen phosphate, potassium hydrogen phosphate, copper phosphate, silver phosphate, magnesium phosphate, calcium phosphate, zinc phosphate, phosphoric acid Cobalt, nickel phosphate, phosphoric acid, diethyl phosphate, triallyl phosphate, triisopropyl phosphate, di-n- phosphate
Examples include butyl, sodium tripolyphosphate, sodium trimetaphosphate, trimethyl phosphite, tri-n-butyl phosphite, and the like. Among these, ammonium hydrogen phosphite, ammonium hydrogen phosphate, copper phosphate, manganese phosphate, ammonium phosphite, ammonium phosphate, phosphoric acid, and phosphorous acid are preferred. These compounds may be used alone or in combination of two or more. The appropriate amount of these catalysts to be used is a molar ratio of 0.01 to 1 with respect to diethanolamine. If the amount is less than this range, sufficient catalytic activity will not be obtained and the reaction rate will decrease. On the other hand, if the amount is too large, the decomposition and polymerization reaction of diethanolamine will be accelerated, which is not preferable. Particularly preferred is a molar ratio of 0.05 to 0.5. Since the catalyst used does not require a separation operation, there is no need to particularly consider the economic efficiency of the amount used, and an appropriate amount within the above-mentioned range is used. The ammonia used in the method of the present invention may be liquid ammonia, gaseous ammonia, or hydrated ammonia. Liquid ammonia is particularly suitable. The amount of ammonia necessary for the reaction is preferably such that an excess of ammonia is present in order to obtain diethylenetriamine in a good yield, and the molar ratio of ammonia to diethanolamine is in the range of 5 to 35. If the amount of ammonia is too less than this range, by-products such as cyclic amines will increase, and if it is too much, a large amount of ammonia must be recovered, which is economically disadvantageous. A molar ratio of 10 to 20 is particularly suitable. Further, it is preferable to carry out the reaction by adding water to the reaction system in an amount of 5 to 40% by weight. When the amount of water contained in the reaction system is less than 5% by weight, the ammonia concentration in the liquid decreases and the reaction rate slows down. Further, intramolecular condensation of diethanolamine progresses and piperazine increases. Meanwhile, 40% by weight
When the amount increases, the hydrolysis reaction of diethanolamine becomes significant, and the selectivity of diethylenetriamine decreases. The reaction temperature of the method of the present invention is in the range of 260 to 290 °C,
Preferably it is in the range of 270 to 280°C. At temperatures below 260°C, the reaction rate becomes extremely slow and is not practical. On the other hand, at temperatures exceeding 290°C, side reactions such as the production of cyclic amines such as piperazine, decomposition of diethanolamine, and polymerization reactions become significant, resulting in a decrease in the yield of diethylenetriamine. The reaction pressure may be higher than the pressure at which the reactant is present in a liquid state. 150~ to obtain sufficient reaction rate
A pressure of 350 kg/cm ² G is suitable. Especially from 200
A pressure of 300 kg/cm ² G is preferred. The method of the present invention can be carried out using a known batch-type or continuous-type reaction apparatus. For example, using such a reactor, a homogeneous or suspended raw material solution containing a catalyst is supplied to the reactor, where diethanolamine and ammonia are catalytically reacted, and the resulting reaction solution is then treated as a normal solution. Separate the reaction products by distillation, extraction, etc. The unreacted raw material containing the catalyst is recovered and returned to the reactor and can be used repeatedly without separating the catalyst. Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples. Example 1 A stainless steel autoclave with an internal volume of 1 was charged with 75.5 g of diethanolamine, 157.3 g of water, and 47.5 g of diammonium phosphate, and after replacing the air in the space with N ₂ gas, 367.2 g of liquid ammonia was introduced under pressure. Rapidly heat and raise the temperature while stirring to a temperature of 270
The reaction was carried out at ℃ for 5 hours. The pressure at this time is 270Kg/
It was cm ² G. After cooling, unreacted ammonia gas was removed, the pressure was returned to normal, and 480.4 g of the reaction solution was recovered. This operation was repeated a total of three times. These three reaction solutions were combined, and dissolved ammonia and most of the water were stripped off by simple distillation. The remaining reaction solution
The mixture was placed in a 500 ml round bottom flask and vacuum distilled using a Widmer distillation column with a height of 50 cm. First, after distilling off low-boiling fractions such as water, ethylenediamine, monoethanolamine, and piperazine, 55.0 g of a fraction with a pressure of 100 mmHg and a tower top temperature of 140 to 142°C was obtained. Analysis of this fraction by gas chromatography revealed that the concentration of diethylenetriamine was 95% by weight, and the rest were monoethanolamine and N-aminoethylethanolamine. In addition, when the remaining liquid was analyzed in the same manner, 82% by weight of diethanolamine remained. As a result,
45% of the diethanolamine was reacted and the selectivity for diethylenetriamine was 55%. Example 2 In a 100ml shaking stainless steel autoclave, add 11.5g of 85% diethanolamine aqueous solution and ammonium phosphate to diethanolamine.
A 0.1 molar ratio (1.2 g) was charged. After purging the air in the autoclave space three times with nitrogen gas, 20.5 g of liquid ammonia (ammonia:dietatriamine = 11:1 molar ratio) was injected under pressure. Thereafter, the autoclave was rapidly heated to raise the temperature, and the autoclave was shaken at 270° C. and 228 Kg/cm ² G for 4 hours.
After rapidly cooling the autoclave, the reaction solution was extracted and the product was analyzed using a gas chromatograph. A diethanolamine conversion rate of 55% and a diethylenetriamine selectivity of 48% were obtained. A large amount of N-aminoethylethanolamine and small amounts of ethylenediamine, monoethanolamine and piperazine were produced as by-products. Example 3 In a 100 ml shaking stainless steel autoclave, 3.7 g of diethanolamine, 2.2 g of H ₂ O and ammonium phosphate were added to diethanolamine.
0.3 mol (1.4 g) was loaded. After purging the air in the autoclave space three times with nitrogen gas, 18.0 g of liquid ammonia (ammonia:diethanolamine = 30:1 molar ratio) was injected. Thereafter, the temperature of the autoclave was rapidly raised, and the autoclave was shaken at 270° C. and 235 kg/cm ² G for 6 hours. After rapidly cooling the autoclave, analysis was performed in the same manner as in Example 2, and a diethanolamine conversion rate of 41% and a diethanolamine selectivity of 56% were obtained. N-aminoethylethanolamine and small amounts of monoethanolamine and piperazine were obtained as by-products. Example 4 A test was conducted in the same manner as in Example 2, using different catalysts and reaction conditions, and the results are shown in Table-1.

[Table] Comparative Example Diethanolamine, ammonia, water, and a catalyst (ammonium hydrogen phosphate) were charged into a 100ml shaking stainless steel autoclave according to the method shown in Example 2, and the reaction was carried out under the conditions shown in Table 2. . After the reaction, the reaction solution was extracted and analyzed by gas chromatography, and the results are also shown in Table 2.

【table】

Claims (1)

[Claims] 1. Diethanolamine and ammonia at 1:5
A method for producing diethylenetriamine, which comprises reacting in a liquid phase in the presence of a phosphoric acid compound or a phosphorous acid compound at a molar ratio of ~1:35. 2. The method according to claim 1, wherein the reaction temperature is 260 to 290°C. 3. The method according to claim 1 or 2, wherein the reaction pressure is 150 to 350 Kg/cm ² . 4. The method according to claim 1, 2 or 3, wherein the reaction is carried out in the presence of 5 to 40% by weight of water.