FI61684C - FOER FARING FRAMSTERING AV SECONDARY ALIPHATIC AMINER - Google Patents

Description

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Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) P 2255701.3 (71) Hoechst Aktiengesellschaft, Postfach 80 03 20, 6230 Frankfurt (Main) 80, Non-Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) (72) Heinz Muller, Burgkirchen / Alz, Engkir, Engz, Engkir / Alz,

Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) (TM Oy Kolster Ab (5 * +) Method for the preparation of secondary aliphatic amines -Förfarande för framställning av secondary secondary aliphatic aminer

The invention relates to a process for the preparation of secondary aliphatic amines having 7 to 24 carbon atoms in the aliphatic chains, from the corresponding primary alcohols or mixtures of such alcohols and ammonia at approximately normal pressure and elevated temperature in the presence of a hydrogenation-dehydrogenation catalyst at a temperature and a pressure of 0.5-6 ätm.

The conversion of alcohols to amines by aminolysis with ammonia alone or with ammonia and hydrogen is known. According to the known methods of the parents, the reaction is carried out continuously using a dehydration catalyst such as alumina in the gas phase and preferably at normal pressure. Newer processes use hydrogenation-dehydrogenation catalysts, such as nickel and cobalt catalysts, and work in the liquid phase from normal pressure - up to 300 atm (see Houben-Weyl, "Methoden der organischen Chemie", 1957, Band 11/1, Nitrogen Compounds II, 15, page 118 2 616 8 4 and Table 18, page 130, in addition DE application publication 1 950 604).

It is known from known publications that the unpressurized aminolysis of higher alcohols generally results in mixtures consisting of primary, secondary and tertiary amines. The process can also be controlled to form predominantly tertiary amines. By contrast, the aminolysis of higher alcohols with the intention of forming primarily secondary amines at low pressure or normal pressure or at a slight overpressure is not known.

According to U.S. Pat. No. 2,078,922, Example 3, octadecyl alcohol is reacted with ammonia using an alumina catalyst in the gas phase at normal pressure and 360 ° C with a reaction rate of only 45% as a mixture of mono-, di- and trioctadecylamines. Example 1 of U.S. Patent No. 2,953,601 shows that unpressurized aminolysis in the gas phase no longer proceeds normally from isooctyl alcohol. The reaction rate is only 10% and hydrocarbons and aldehydes are formed as by-products in the reaction.

Thus, the high-tech preparation of high molecular weight secondary aliphatic amines by the gas phase method has not been considered before. Unpressurized aminolysis of higher alcohols with ammonia in the presence of hydrogenation-dehydrogenation catalysts gives a mixture of 17% primary, 22% secondary and 31% tertiary from lauryl alcohol at 165 ° C according to Example 20 of U.S. Patent 3,223,734, using Raney nickel. The reaction rate is 70% based on alcohol.

It follows that tertiary rather than secondary amines are formed in such a reaction. Thus, unpressurized aminolysis of higher alcohols has been economically feasible only to produce tertiary amines (see, e.g., DE-A-2,050,866 and U.S. Pat. No. 2,953,601).

The economical preparation of higher secondary amines from the corresponding primary alcohols by aminolysis at normal pressure or up to 5 atm overpressure is not known. However, there are aminolysis methods for the preparation of secondary amines which, however, are uneconomical and have low yields and incomplete reactions (see U.S. Patent Nos. 2,636,902, 3,022,349 and 3,080,424).

DE 61,684 DE 950 604 relates to a process for the preparation of amines in the reaction of alcohols and ammonia or in the reaction of alcohols, amines and hydrogen in the presence of a solid catalyst containing cobalt.

DE-A-1 493 781 deals in detail with the aminolysis of secondary alcohols with ammonia at normal pressure with nickel-cobalt and copper chromite catalysts. From the comparative experiments performed between octanol-1 and octanol-2, it can be concluded from the low reaction rate of octanol-1 of 16% and octanol-2 of 72% that "ammonia does not react according to the invention. with primary alcohols in an efficient manner under process conditions ’.

Contrary to DE 1 950 604 that in order to obtain higher secondary amines it is necessary to carry out the aminolysis by a two-step process at 300 atm overpressure, and contrary to DE 1 493 781, primary alcohols can be converted to normal , it has now been found that higher secondary amines can be obtained very advantageously from the corresponding primary alcohols under normal pressure or mild underpressure or overpressure in good yield if the aminolysis is carried out at a gas rate of 50-1200 l / h per kg of alcohol and ammonia and that the volume ratio of hydrogen throughout the reaction is 80:20 to 20:80 and that the resulting water is removed with the gas stream.

The starting materials used in the process according to the invention are straight-chain and / or branched, saturated or unsaturated primary alcohols having 7 to 24 carbon atoms, such as, for example, octanol-1,2-ethylhexanol, isooctyl alcohol, isononyl alcohol, isononyl alcohol, lauryl alcohol, lauryl alcohol oleyl alcohol, stearyl alcohol, further mixtures of these alcohols, in particular those formed by the hydrogenation of natural fatty acids or their esters, such as, for example, tallow fatty alcohol and palm kernel fatty alcohols. In addition, commercially available ethylene-structured alcohols from the Ziegler process, which produce saturated primary alcohols up to 24 carbon atoms, are very suitable. Also more or less branched alcohols, such as those formed in various 4 61 6 δ 4 oxoprocesses from straight-chain and branched olefins, and isooctadecyl alcohol prepared from isononylaldehyde are suitable starting materials for the preparation of secondary amines according to the invention.

Preferred, technically readily available primary alcohols thus contain 7, 7-9, 9-11, 12-13, 13, 12-15 or 16-19 C atoms, the mixtures mainly containing compounds with an odd C number. , on the other hand, compounds containing 8, 10, 8-10, 12-14, 16, 14-18, 16/18, 14-20, 18-22 or 20-24 carbon atoms are readily available, in which case the mixture unfortunately contains compounds with an even number C. Of course, individual alcohols having 7 to 24 carbon atoms alone or added to mixtures can also be used. In any case, the aliphatic chains may be straight or singly or multiply branched and saturated or singly or multiply, preferably simply unsaturated.

Suitable dehydrogenation catalysts are nickel catalysts, both in the Raney type and in granular or powder form, with or without a support. Further suitable are the corresponding cobalt catalysts and catalysts containing nickel and cobalt, optionally in admixture with copper, as well as highly complex catalysts, e.g. catalysts consisting of copper and chromium, in addition to alkalis, barium and other metals.

In a preferred embodiment of the invention, an alcohol and a catalyst are passed through a flask containing e.g. stearyl alcohol and Raney nickel at 180-200 ° C with good stirring of ammonia and hydrogen. In this embodiment of aminolysis, due to the partial loss of dehydrogenation hydrogen, it is necessary to introduce hydrogen into the system with ammonia for good yield of the secondary amine, in which case it is irrelevant whether the hydrogen is introduced immediately at the beginning of the ammonia or during the reaction; however, the addition should begin when about 1/4 of the total reaction time of about 3-4 hours has elapsed.After about 2 hours the actual amination is complete, and then it is preferred to complete the hydrogen alone to complete the hydrogenation. -lyysis can be carried out by working from the beginning of the reaction 5 616 8 4 with a constant ammonia-hydrogen ratio, in which case an ammonia-hydrogen volume ratio of 50:50 proved to be suitable, but it is also possible to work with varying volume ratios.

In order to carry out the reaction, it is necessary that ammonia and hydrogen are both present in a sufficient amount.

50 1 gas / h per kg of alcohol is then the lower limit. The upper limit of the amount of gas is mainly determined by the process technology and the cost. Thus, gas rates above 1000 1 / h per kg of alcohol, e.g. 1200 1 / h.kg, are possible. However, the rate must not be so high that the partial pressure of the alcohol drops so sharply that the temperature required for the reaction is no longer reached and / or the alcohol continues to pass into the collecting vessel. In most cases, for lower alcohols having about 8 carbon atoms, as well as for higher alcohols having, for example, 24 carbon atoms, with a reaction time of about 2-4 hours, gas amounts of 150-300 l / kg of alcohol have proved very advantageous.

Crucial to the aminolysis of secondary amines is that the minimum amounts of gas are not exceeded, because then there is a risk that the proportion of tertiary amine will become too high. Also, an excessive reduction in the amount of gas, especially towards the end of the reaction, may make it difficult to achieve an optimal secondary amine content. In these cases, the secondary amine formed reacts relatively rapidly on its own, forming tertiary amines and non-amine by-products, such as hydrocarbons, nitriles and the like. If too little ammonia or a mixture of ammonia and hydrogen is already present at the beginning of the reaction, the secondary amines already formed can also react with the alcohol still present in the mixture and the primary amines formed to form undesired tertiary amines.

The process of U.S. Patent No. 2,953,601 apparently involves too little ammonia. Although it also undergoes aminolysis to higher alcohols, namely iso-C8 alcohol and iso-C 1-4 alcohol under pressure under ammonia and Raney nickel in the liquid phase at 165-190 ° C, it yields mainly tertiary amines. A further disadvantage of this method is that it works without additional hydrogen. Thus, recourse must be had only to dehydrogenation hydrogen, which, as already stated above, is constantly wasted in the 6 616 8 4 "open" reaction described above. The secondary formation of amines according to the invention is therefore impossible according to this known method.

Comparing Example 3 of U.S. Patent No. 2,953,601 to Example 1 of the process of the invention results in the following amine composition for isooctylamine: U.S. Patent No. 2,953,601 Example 3 Example 1

Iso-octylamine ----------- 4% di-isooctylamine 20% 85% tri-isooctylamine 65% 8% by-products 15% 3%

In addition to the low formation of secondary amines in the process of U.S. Patent No. 2,953,601, hydrogen and ammonia deficiency also results in the formation of tertiary amines containing OH groups by condensation of aldehydes, which OH groups react in aminolysis as well as the OH groups of the alcohol originally used. Instead, with the timely and adequate supply of ammonia and hydrogen, hydroxyamines are not formed.

The great importance of hydrogen could be demonstrated in two comparative experiments: In the first experiment, stearyl alcohol was subjected to aminolysis at 180-200 ° C in the presence of Raney nickel (2%) at 200 l of ammonia / h of alcohol per kg of alcohol. Only 12% of secondary distearylamine and 35% of neural substances, which were predominantly nitriles, were formed. In the second experiment, ammonia and hydrogen were used in the absence of nitriles; other neutral substances were obtained 3.5% and secondary distearylamine 88%.

These experiments show that this non-pressurized aminolysis of alcohols having 5 to 13 carbon atoms according to U.S. Patent No. 2,953,601 is also not suitable for the preparation of secondary amines containing more than 13 carbon atoms from the corresponding primary alcohols.

In the process according to the invention, in which secondary amines are obtained in good yield, both relatively short-chain alcohols, for example C 1-4 alcohols, and also long-chain alcohols, such as, for example, C 2 -C 4 alcohols, can be used. However, it is expedient to react short-chain C 1 -C 4 alcohols with different catalysts and under different reaction conditions than long-chain ones if equal proportions of secondary amines are to be obtained. Short-chain alcohols are more reactive and are therefore conveniently treated with more inactive hydrogenation-dehydrogenation catalysts than slow long-chain alcohols having 16 to 24 carbon atoms. As a rule of thumb, the product of the reactivity of the alcohol used and the activity of the catalyst is constant, for example, a high-activity Raney nickel suspension is suitable for stearyl alcohol and an inactive nickel powder catalyst for octanol. Water-coated Raney nickel catalysts can be used in the original wet state.

The catalyst is usually required per batch of 2-3% by weight of the amount of alcohol. With relatively short chain C 1 -C 4 alcohols, which are preferably treated with more inactive catalysts, it has proven advantageous to use about 5% catalyst. By reusing 90-95% of the spent catalyst and adding a little new catalyst to each charge, the consumption of the catalyst in continuous use always results in 0.3% by weight of alcohol, depending on the alcohol and the catalyst.

The optimum reaction temperature for aminolysis depends on the activity of the catalyst and the reactivity of the alcohol, which in turn depends on the chain length and structure. It proved advantageous to adjust the temperatures of the reactants so that the reaction takes place at 190-200 ° C. For β-alcohols, this temperature cannot be used from the outset, because the boiling points of these relatively low-boiling alcohols fall optimally to 140-150 ° C in the presence of the required amount of ammonia and hydrogen. Therefore, it is suitable to use relatively small amounts of gas initially, e.g. to start at 120 ° C with 50 l of gas / kg of C 1-4 alcohol / h and to raise the temperature when the boiling point is due to the continuous formation of secondary amines and their precursors. elevated. It is also possible to start with the optimum amount of gas at a temperature of 120 ° C immediately and only then to raise the temperature slowly. With these reaction methods, the desired temperature of 190-200 ° C is reached with the C 1-4 alcohol about half an hour to 1 hour later than in the case of high-boiling alcohols.

616 8 4 8

The temperature above the boiling point can also be adjusted by initially working at a slightly elevated pressure, e.g. about 0.5-1 atm overpressure. In the case of stearyl alcohol, the optimum temperature of 190-200 ° C can be adjusted immediately and without special measures.

The measure of the completion of the actual amination reaction is the amount of water separated, which is collected in a collection vessel as ammonia water. In the case of lower alcohols in particular, volatile organic constituents such as unreacted alcohol and primary amines are also separated with the reaction water. The cooler can be used to reduce the loss of organic products. They are separated from the water and returned continuously or non-continuously to the reaction vessel. The amount of water obtained in the process according to the invention is practically the same as calculated theoretically, because on the one hand the alcohol reacts completely and on the other hand due to the large ammonia-hydrogen supply no secondary condensation to hydroxyamines takes place.

The water of reaction formed must be continuously removed from the reaction mixture. Water vapor escapes with hot gas, ammonia and hydrogen either directly or through a condenser. The gas mixture consisting of ammonia and hydrogen may also contain an inert gas such as N 2 and / or CH 2 Cl 2 and is not always saturated with water vapor.

After about 90% of the reaction water has been separated, it is preferred to lower the temperature to about 175 ° to 180 ° C. During this step, as was noted, the hydrogenation of predominantly nitrogen-containing condensation products, such as Schiff's bases, to secondary amines takes place. In the final stage of the reaction, it is therefore advantageous to increase the proportion of hydrogen, or to use pure hydrogen.

The complete reaction takes about 2-4 hours. In the case of C 1 -C 4 alcohols, the reaction is initially slow and a longer reaction time is required to reach the required reaction temperature.

The aminolysis of higher alcohols according to the present invention is usually carried out at normal pressure. This is true both in the "open" reaction mode and also in the "closed" circulating gas reaction mode, which will be explained later. However, at the beginning of the reaction, it may be advantageous to adjust the vacuum to a maximum of about 0.5 atm (about 380 mm Hg), at lower pressures the partial pressures of ammonia and hydrogen drop sharply, and in addition the boiling point of the alcohol used may fall below the reaction temperature. The advantage of a slight pressure rise at the beginning of the aminolysis to raise the reaction temperature has already been discussed above in connection with relatively low boiling C 1 -C 1 alcohols. Towards the end of the reaction, which is primarily a matter of catalytic hydrogenation, the increase in pressure causes a shortening of the time. Finishing takes place at an overpressure of up to 6 atm. Whether I 1 is used alone or + NH 4 is then used depends on the degree of aminolysis that has already taken place, i.e. replacement of the OH group of alcohol with nitrogen. Increasing the pressure towards the end of the reaction is suitable when starting from unsaturated alcohols and it is desired to obtain highly saturated secondary amines.

A preferred embodiment of the process according to the invention is the so-called "circulating gas" - or "closed" reaction method, in which - in contrast to the "open" reaction method - ammonia and hydrogen are circulated so that they are practically not wasted. This results in equal yields of secondary amines with substantially lower amounts of both gases.

In addition, it has been found that the circulating gas process survives even without the addition of hydrogen. In contrast to the "open" process, the hydrogen from the dehydration of the reaction process is sufficient to achieve the ammonia-hydrogen ratio required in the preparation of secondary amines according to the invention. The fact that no additional hydrogen is needed is very beneficial economically.

The following comparison shows the advantage of a "closed" way of working compared to an "open" way of working. Both experiments were performed using stearyl alcohol as a model in the presence of Raney nickel (2%) at normal pressure and 200 ° C at a gas volume of 200 l / h per kg of stearyl alcohol and a reaction time of 4 hours. The experiments were performed with pure ammonia, i.e. without the addition of hydrogen.

10 61 684

Table "open reaction" closed reaction 100% nh3 100% nh3% primary amines 18% 6.3%% secondary amines 12% 84.5%% tertiary amines 28% 3.2%% total amines 58% 94%% non- amine compounds 35% 4%% unreacted alcohol 6% 0.5%

Carbonyl number 1) 1.5% CO <0.25% CO

1) The carbonyl number indicates the number of Schiff bases still remaining, calculated as% CO. 1.5% CO corresponds to about 15% primary amine or 30% secondary amine.

The results again show that the "open" reaction with ammonia alone is not suitable for the preparation of secondary amines. However, since in the "circulating gas" reaction mode the partial pressure of the dehydrogenation hydrogen decreases as the reaction continues and thus the hydrogenation found to be advantageous slows down at the end of the reaction, it has proved advantageous in practice to introduce a certain amount of foreign hydrogen into the reaction. This shortens the reaction time, increases the yield of secondary amines and reduces the formation of neutral substances. If, for example, the "closed" reaction method is varied according to the above experiment so that after a reaction time of 2-3 hours the hydrogen partial pressure is increased to increase the foreign hydrogen from about 25% to 80%, then instead of 84.5% secondary amines are obtained. , 6%. The amount of neutral substances decreases from 6% to 2.4%. The overall reaction rate to amines increases from 94% to 97.6%. The carbonyl number, which is a measure of non-hydrogenated Schiff's bases, disappears virtually completely from 0.25% (corresponding to 5% secondary distearylamine) to 0.01%.

The technical treatment of this after-treatment with hydrogen can take place, for example, by separating the ammonia from the circulating NH3-H2 mixture more or less completely, e.g. by freezing or washing, and replacing it with hydrogen.

The figure illustrates the execution of the "circulating gas" reaction method by hardware. The apparatus comprises, for example, a 100 liter 61 6 8 4 1 1 mixing boiler 1 with a packing column 2, a circulating gas blower 3 and a circulating gas piping 4 for recycling ammonia, hydrogen and possibly inert gases, a condenser 5, a water and volatile organic matter separator 6 and inlet lines NH Ile 7, H ^ slle 8 and possibly lie 9 (as a purge or possibly as an inert gas addition) and an exhaust gas line 10. The boiler is heated and cooled by a jacket 11. From the cooler 6 a line 12 leads back to the boiler 1, through which the organic phase 14 separated from the aqueous phase 13 back.

Of course, other types of equipment can also be used in the method according to the invention.

The figure also illustrates the open reaction described above. In this case, a circulating gas blower is not used, but the gas is removed via an exhaust gas line.

The operation of the circulating gas apparatus is described below using long chain alcohol as an example. 50 kg of alcohol and the catalyst are heated to about 120 ° C, and the reaction is started with pure ammonia at a circulation of 10-15 m / h. The required temperature of 200 ° C has been reached within 1 hour. The reaction water passes with the circulating gas to the condenser 5, where it is condensed and separated in a collecting vessel 6. Any entrained organic matter is returned to the process via a connecting line 12 to the boiler. The required pressure in the equipment is regulated by re-supplying NH 4. At the end of the 1 hour heating step, the proportion of ammonia in the circulating gas is only about 30%; 70% is hydrogen derived exclusively from dehydration of alcohol. After a further 1-2 hours, the proportion of hydrogen has decreased to about 25% due to hydrogenation in the circulating gas. The reaction temperature is then lowered to 180 ° C, and during the last 30-60 minutes the proportion of hydrogen in the circulating gas can be increased by adding hydrogen. Hydrogen can also be added at the beginning or during the reaction.

After completion of the aminolysis, the catalyst is filtered off. About 5-10% of it will be replaced with a new catalyst. In this way, the renewed catalyst goes back to the process. The 25 "circulating gas" mixtures of 50 kg had an average catalyst consumption of 0.23%.

12 61 6 8 4

In addition to the open and closed reaction method, the aminolysis according to the invention can also be a mixed form of both methods. It is a mixed form in certain cases of the circulating process, where e.g. the gas circulating in the apparatus is completely or partially replaced by hydrogen at the end of the reaction and the corresponding amount of gas is removed at the same time, thus working "openly"! The mixed process is also a continuous gas extraction process. replaced with fresh gas.

A change in the composition of the gas in a closed circulating gas apparatus filled with, for example, NH 4 and Ut, can also occur by increasing the pressure to increase the pressure, or by increasing the volume of the circulating gas by including a correspondingly filled spare vessel in the circulating gas system. The open, closed, and mixed methods are described as applied to the batch mode. Of course, it is also possible to carry out the process according to the invention completely or partially continuously, e.g. in a piping system, in several reactors connected in series or in boilers arranged in a cascade. From the required gas (NH 2 + H 2), the water formed or entrained can always be separated in a cascade sequence or other stepwise reaction mode before it enters the next reactor. The final reactor of the final stage of the process can be used under other conditions. Instead of 200 ° C, the temperature may be 180 ° C and pure hydrogen may be used as the gas mixture instead of NH 4 and E 2. The final reaction time, which is shorter than the reaction time of the main reaction, is achieved by the correspondingly smaller reaction time.

In addition to suspended and pumpable catalysts, solid, granular or wirewound catalysts can also be used in the continuous process.

The above open, closed and mixed process information on gas composition, gas volume, pressure and temperature, and other factors also apply to the continuous and other methods of the present invention.

Depending on the alcohol used, the catalyst and the process conditions, secondary amines can be obtained in the process according to the invention in concentrations of 80-95%. It has been shown analytically that the content of unreacted alcohol is less than 1%. The sum of the neutral substances is about 1-5%, depending on the alcohol and process conditions. The products obtained are very good in color. Their iodine color numbers (determined by the iodine color scale: DIN 6162) are 0.5-1. The secondary amines obtained do not generally need to be purified by adsorption or distillation before further processing.

Secondary amines derived from primary alcohols from di-heptylamine to di-C2-4-amine are, alone or in mixtures, e.g. desired intermediates in the preparation of quaternary ammonium compounds (with 2 long-chain and short-chain residues). These, in turn, are used e.g. as a plasticizer in textiles (fabric softener rinse aid), as components in organophilic ammonium bentonites and as moth repellents and raw materials in cosmetics, in particular for hair treatment.

In the following examples, the method is performed at normal pressure, unless otherwise indicated.

Example 1

The experiment is performed in the "open" reaction mode in a 100 L stirred pot according to the order of the diagram. A circulating gas blower is not used in the present case, and the excess gases, NH 4 and are discharged through the exhaust pipe.

The mixing boiler is charged with 50 kg of isooctyl alcohol (a mixture of C8 alcohols from branched oxosynthesis, mainly isomeric dimethylhexanols). By purging the reaction space with nitrogen, 2.5 kg of Raney nickel powder ("B 213" from Firma DEGUSSA) are added. The boiler is then closed. With good stirring and at the same time conducting nitrogen, the mixture is heated and at 120 [deg.] C. an NHg / H2 mixture (1: 1) 50 l / h per kg of alcohol is introduced. The amount of gas is gradually increased to 250 1 / h. kg until a reaction temperature of 200 ° C is reached. This state is reached after 3 hours. At 200 ° C, an ammonia / hydrogen mixture is introduced over the next 1.5 hours. The separation of the water is practically over by this time. Finally, treat for a further 1 hour with 250 liters of hydrogen / h and per kg of alcohol at 200 ° C. The hot reaction gases, together with the water vapor formed, are cooled after being removed from the boiler in a condenser at 20-25 ° C, 14 616 8 4, whereupon the excess organic matter condenses in a separator. The separated organic matter is continuously recycled from the separator to the boiler. At the end of the reaction, 9.1 l of ammonia water had separated. After cooling the contents of the boiler to 100 °, the catalyst was filtered off. The filtrate contained 42 kg of amine. The analysis was as follows: primary iso-octylamine 4% secondary di-isooctylamine 85% tertiary tri-isooctylamine 8% non-amine compounds 3% with <0.5 residual alcohol

A similar result is obtained with a technical C 1 -C 6 alcohol mixture.

Example 2

In the same apparatus as in Example 1, aminolysis was performed on technical olenyl alcohol having an iodine value of 71. 50 kg of oleyl alcohol was weighed into the kettle, the kettle was purged with nitrogen and 1.5 kg of moist Raney nickel catalyst ("B 113" from DEGUSITSA) was added. was about 70%. At 100 °, a mixture of NH 4/1 2 (1: 1) 240 l / h.kg of alcohol was started. After 1 hour, a reaction temperature of 200 ° C was reached; by this time 1.5 L of ammonia water had formed in the separator. At 200 ° C, aminolysis was performed with 240 liters of the same gas composition as before for another 2 hours. A total of 4.8 l of ammonia water was formed. Finally, it was cooled and the catalyst was filtered at 80-100 ° C. 46 kg of amine were obtained. Analysis: primary amine 3% secondary amine 87% tertiary amine 7% non-amine compounds 3% containing <0.5% residual alcohol.

The iodine value was 63.

Example 3

The procedure was as in Example 2, but to save hydrogen, in contrast to Example 2, a gas mixture consisting of ammonia, hydrogen and nitrogen in a volume ratio of 40:40:20 was used in this experiment. In this case, the amine yield did not change at all.

616 8 4 15

Otherwise, under the same conditions, the following result was obtained: primary amine 5.5% secondary amine 84% tertiary amine 6% non-amine compounds 4.5%

The iodine value was 67.

Example 4 200 g of decanol were carried out in the "open" reaction method by aminolysis in a glass apparatus with the addition of 10 g of a stabilized nickel catalyst ("B 213" from DEGUSSA). The apparatus consisted of a 500 ml four-necked flask with a stirrer, a thermometer, an inlet pipe for ammonia and hydrogen, and an outlet pipe connection connected directly to a graduated water separator. This was equipped with a reflux condenser with an outlet pipe.

The apparatus was purged with nitrogen, heated and, at 130 ° C, 20 l / h of ammonia and 20 l / h of hydrogen were introduced with stirring. Heating to about 170 ° C took 100 minutes. An additional $ 1 hour was required for the reaction temperature of 200 ° C. At this temperature, the addition of ammonia and hydrogen was continued for the next 90 min. In this case, the water separation was complete and instead of ammonia and hydrogen, 20 l of hydrogen were finally passed in over an hour. Finally, it was cooled to 80 ° C and the catalyst was filtered off. The yield was 158 g.

The decanol partially separated in the reaction with water accumulated at the top of the separator and continuously flowed back into the reaction flask. Analysis gave: primary monodecylamine 2.8% secondary di-decylamine 85.9% tertiary tri-decylamine 7.4% non-amine compounds 4.0% residual alcohol 0.5%

A similar result is obtained with a technical mixture of q-C1-4 alcohol.

Example 5

In a manner similar to Example 4, 200 g of iso-tridecyl alcohol was converted to the secondary di- (iso-C 1-4 amine).

16 61684

5.7 g of wet Raney nickel ("B 113" from DEGUSSA) corresponding to 4 g of nickel was used as catalyst. The heating period to 200 ° C took place under the conditions of Example 4, at the same time giving 20 l / h of ammonia and 20 l / h of hydrogen.

After 1 hour, a temperature of 200 ° C was reached, at which time the reaction was allowed to proceed for another 2 hours. The separation of the water was then complete. Finally, hydrogenation was continued for 1 hour at 190 ° C with 20 liters of hydrogen. After filtration of the catalyst, 171 g of iso-tridecylamine were obtained. Analysis gave: primary iso-C 1-4 amine 7.4% secondary iso-C 1-4 amine 85.6% tertiary iso-C 1-4 amine 1.9% non-amine compounds 5.1% residual alcohol <0.5%

Example 6

Aminolysis was performed in a small circulating gas apparatus assembled from glass sections according to the diagram of the figure. A hose pump was used instead of a circulating gas fan for the technical equipment.

The reaction flask was filled with 400 g of stearyl alcohol and 10.8 g of wet Raney nickel (8.0 g Ni), the apparatus purged with nitrogen and heated. At 100 ° C, the nitrogen was removed with ammonia and the stirrer and circulating pump were started. By adding ammonia at a pre-pressure of 25 mmHg and removing some gas from the apparatus, a reaction temperature of 200 ° C was reached within 1/4 hour. The degassing was stopped and the equipment remained connected to the ammonia supply line. Ammonia consumption was also measured continuously. The amount of circulating gas was 100 1 / h. After 3 hours, the separation of water and the binding of ammonia had ceased. Finally, work was carried out for another 1 hour at 200 ° C, increasing the circulation gas volume to 120 l / h. The volume ratio of ammonia: hydrogen in the gas cycle was 46:54 after a reaction time of 1 1/4 hours and 74:26 after 3 hours. After 4 hours, the mixture was cooled and the catalyst was filtered off. The yield was 372 g. Analysis gave 94% reaction to amine: primary stearylamine 6.3% secondary distearylamine 84.5% tertiary tristearylamine 3.2% non-amine compounds 6.0% 61 6 8 4 17

The same experiment was repeated in a slightly modified form, adding foreign hydrogen in the last step of the 4-hour reaction. In this case, after a reaction time of 3 hours, the gas contained in the apparatus was changed to a gas mixture consisting of 80% by volume of hydrogen and 20% by volume of ammonia. This gas mixture was worked for 1 hour under otherwise the same conditions as in the above experiment, namely at 200 ° C and a flow rate of 120 l / h.

By this procedure, 97.6% could be converted to the amine, and the yield of the secondary amine was improved. The amine distribution was as follows: primary stearylamine 3.2% secondary distearylamine 91.6% tertiary tristearylamine 2.8% non-amine compounds 2.4%

Example 7

50 kg of molten myristyl alcohol (tetradecanol) was placed in a 100 l mixing boiler of the circulating gas apparatus according to the diagram. Nitrogen purging was performed by starting a circulating gas fan. The catalyst was weighed and heated as in Example 1. The catalyst was nickel powder on the surface of the support ("RCH nickel contact 55/5" Ruhrchemie), and 1.2 kg was used. After removal of nitrogen with ammonia, the circulating gas was adjusted to 120 m / h at 120 ° C.

After 1 hour, the required reaction temperature of 200 ° C was reached; the pressure in the apparatus was maintained by dispensing NH 2 with a pressure control valve at normal pressure. At 200 ° C and 12 m circulating gas / h, the reaction was continued until about 90% of the reaction water (4.2 L) had formed in the form of concentrated ammonia water in the separator. This was achieved after 2 hours. At this time, the circulating gas was replaced with a mixture of I 2 and NH 4 in a volume ratio of 5: 2. At the same time, the reaction temperature was lowered to 180-190 ° C and worked for another 1 hour 3 at 12 m / h circulating gas. Thus the water separation and reaction was complete. Finally, it was frozen and the catalyst was filtered off. The yield was 44.5 kg, the conversion to the amine was 95%.

Analysis: primary amine 4% secondary amine 86% tertiary amine 5% 18 61 6 8 4 non-amine compounds 5% with residual alcohol 1%.

Example 8

The reaction was carried out as in Example 7 with myristyl alcohol, but the pressure conditions were different: instead of normal pressure, an hour-long heating and initial step was performed at 0.8 atm overpressure, and a two-hour main reaction at 0.9 atm overpressure. By this time, the water separation had already been completed, in contrast to Example 7, and was 4.3 l of NH 4 water. The post-reaction with a 5: 2 mixture of 1N / NH 4 is carried out at an overpressure of 1.5 atm. The amine yield was 97% and the secondary amine content was 88%.

Example 9 This experiment was performed as in Example 7 using 50 kg of lauryl alcohol and 2.5 kg of Raney cobalt. The reaction to the amine was 98%. 89% of secondary dilaurylamine was obtained.

Example 10 50 kg of tallow fatty alcohol was subjected to amine lysis in a circulating gas apparatus as in Example 7. Tallow fatty alcohol is a mixture of saturated alcohols obtained by perhydration of tallow fatty acid methyl esters. The chain distribution averages 5% C ^ # 30% and 65% C ^ # g.

The tallow fatty alcohol used in the experiment had an OH number of 215 and a molecular weight of 260. Raney nickel ("B 113" from DEGUSSA) was used as the catalyst, and 1 kg was used as nickel. The packing with starting material, catalyst and NH 4 and heating to 200 ° C took place as in Example 7. The packed column and condenser line were heated to 90 ° C.

3

The amount of circulating gas was 13 m / h. After a reaction time of 2 hours at 4.6 ° C, 4.6 l of ammonia water had formed. At this time, the proportion of hydrogen in the circulating gas was increased from 25% to 70% by the addition of H 2 and NH 4 in a volume ratio of 5: 2 and at the same time the reaction temperature was reduced to 180 ° C by 19 ° C: a. After 30 minutes, 4.95 liters of water had separated and the aminolysis was complete. Finally, it was further cooled to 160 ° C with a gas / NH 4 atmosphere and purged with N 2. At 100 ° C, the catalyst was filtered off. Yield 46.8 kg. The oil entrained in the aminolysis was 200 g and was not returned to the process. The reaction to the amine was virtually complete, 99%. The residual alcohol content was <0.5, below the detection limit.

Analysis: primary amine 3.9% secondary amine 89.8% tertiary amine 5.3% non-amine compounds 1.0% The yield of 46.8 kg could be increased by about 800 g by washing the catalyst residue with isopropanol and distilling off the solvent.

This measure is only relevant for individual bets. Normally, the catalyst is reused with 10-20% of new catalyst. When the amount of catalyst has risen to 5-6% of the alcohol used, this level is maintained by removing the corresponding amount of spent catalyst and adding new catalyst.

Example 11

Following the procedure of Example 10, aminolysis was performed on 50 kg of C22 alcohol with an OH number of 175 (behenyl alcohol) in a circulating gas apparatus. 1 kg of nickel catalyst ("RCH catalyst 55/10" Ruhrchemie) was used as catalyst. In contrast to Example 10, the amount of circulating gas during the heating step and during the main reaction lasting 2 hours was 20 m 2 / h. The purge was performed in this case with pure hydrogen and finally 11a was hydrogenated at an overpressure of 6 atm at 80-200 ° C.

The pressure was then released, cooled to 120 ° C and filtered. Yield: 47 kg, amine reaction 95%. The secondary amine was 83%. The sample taken before post-hydrogenation contained a total of 89% by weight of amines and 73% by weight of secondary di- (behenyl) amine.

A similar result is obtained with the technical alcohol mixture g-C24.

20 61 6 8 4

Example 12

The reaction was carried out as in Example 10. The starting material used was 50 kg of C18-C20 alcohol having an OH number of 218 and prepared by the Ziegler method from ethylene ("Alfol 16/20" from Condea). Instead of the aqueous Raney nickel suspension ("B" 213 firm DEGUSSA), 875 g of nickel powder catalyst ("NP" tirma Unichema) was used. The amine reaction was 97.8%. The secondary amine was 83.2%.

Example 13

To an apparatus comprising a four-necked flask equipped with a stirrer, thermometer, inlet tube for NH 4 and H 2, an outlet tube connection equipped with a reflux condenser heated to 80 ° C, a condenser cooled to it and a reaction water collecting vessel were added 200 g tallow alcohol and 2% by weight of alcohol Raney nickel. The apparatus was heated and purged with nitrogen, from 100 ° C purged with NH 4, and from 150 ° C a mixture of 125 liters of NH 4 and 100 liters of H 2 per hour was passed, and the reaction mixture was heated to 200 ° C. C. The declared amount of gas corresponds to 1125 1 / h. kg of alcohol. After 2.5 h of NH 2 / H 2 at 200 ° C, the separation of water was complete, the ammonia was stopped and the mixture was treated with 100 liters of hydrogen / h for 30 minutes. After filtration of the catalyst, the product had the following analysis: primary amine 2.4% secondary amine 88.4% tertiary amine 6.4% neutral compounds 2.8%

Claims (5)

21 616 8 4 A process for the preparation of secondary aliphatic amines having 7 to 24 carbon atoms in the aliphatic chains from the corresponding primary alcohols or mixtures of such alcohols and ammonia at approximately normal pressure and elevated temperature in the presence of hydrogenation-dehydrogenation catalyst under hydrogenation by reacting the alcohol At a temperature of C and a pressure of 0.5 to 6 atm, characterized in that the gas rate is 50 to 1200 l / h per kg of alcohol and the volume ratio of ammonia to hydrogen throughout the reaction is 80:20 to 20:80 and that the water formed is passed away with the gas flow. Process according to Claim 1, characterized in that the reaction is carried out in the presence of an inert gas. Process according to Claim 1 or 2, characterized in that, towards the end of the reaction, the proportion of hydrogen in the reaction gas is increased, preferably by conducting substantially pure hydrogen as the gas phase. Method according to Claims 1 to 3, characterized in that the gas phase is circulated. Process according to Claim 4, characterized in that the reaction is carried out without the addition of foreign hydrogen.