EP2086920A1

EP2086920A1 - Method for the synthesis of high purity primary diamines and/or triamines

Info

Publication number: EP2086920A1
Application number: EP07866497A
Authority: EP
Inventors: Thierry Beillon; Jean-Philippe Gillet
Original assignee: Carbonisation et Charbons Actifs CECA SA
Current assignee: Carbonisation et Charbons Actifs CECA SA
Priority date: 2006-10-27
Filing date: 2007-10-26
Publication date: 2009-08-12
Also published as: BRPI0717752A2; WO2008053113A1; RU2009119997A; JP5389657B2; US20110190541A1; FR2907781B1; MX2009004502A; IN2009DN02522A; RU2454400C2; JP2010507638A; FR2907781A1

Abstract

The invention relates to a method for preparing high-purity primary di- and tri-amines from nitriles that can originate from dimmer and trimer acids. The method comprises the step of ammoniating the acid functions and the step of hydrogenating the nitrile functions into primary amine functions, and does not require any additional purification step(s).

Description

PROCESS FOR THE SYNTHESIS OF PRIMARY DIAMINES AND / OR PRIMARY TRIAMINES

HIGH PURITY

TECHNICAL FIELD The present invention relates to a process for synthesizing diamines and / or primary triamines from dimeric and / or trimeric nitriles, which nitriles may themselves be derived from dimeric and / or trimeric fatty acids.

These amines find many applications as anticorrosive agents, in the detergency, as additives for bitumen, flotation agents, anti-caking agent, anti-dust, crosslinking agents, petroleum additives, lubricating agents, additives in the treatment of water, additives for concrete.

STATE OF THE PRIOR ART

The diamines and triamines such dimeric and trimeric fatty acids have been known since the 1950s and have an EINECS number and are described for example in Kirk Othmer Encyclopedia, ^4th Edition, Vol. 8, chapter Dimer Acids (pages 223-237).

Dimeric and trimeric acids are obtained by high temperature and pressure polymerization of unsaturated fatty acids. These unsaturated fatty acids, mainly oleic (C: 18-1) or linoleic (C: 18-2) acids, come mainly from tall oil, which is itself derived from pulp processes of the Kraft type. This source of acid is preferred for cost reasons (85% of the acids consumed in this field), but it is quite possible to use unsaturated fatty acids from other vegetable sources. After polymerization of these acids, a mixture is obtained containing on average 30-35% of monocarboxylic acids often isomerized relative to the starting acids, 60-65% of dicarboxylic acids (dimer acids) with twice the number of carbon per molecule. relative to the starting acids and 5-10% of tricarboxylic acids (trimeric acids) having the triple carbon number with respect to the starting acids. Purification of this mixture gives the different commercial grades of dimer and / or trimeric acids which may exist in hydrogenated or non-hydrogenated form.

Among these are the Pripol range developed by Unichema. These products are the compounds of choice for many applications thanks to their properties such as high hydrophobicity, good stability with respect to heat, UV and oxygen, good compatibility with materials.

The major advantage of diacids and triacids lies in the fact that these compounds remain liquid at room temperature while having a low viscosity despite their average carbon number of 36 or 54. This is due to the mixture of the many isomers that constitute the product as well. than cycloaliphatic rings and the presence of unsaturations. In addition, most diacids and triacids are derived from vegetable raw materials and therefore renewable.

The synthesis of these amines, from fatty acids which are first di- or tri-merized, takes place in two stages: conversion of the carboxylic functions to nitrile functions by the action of ammonia in the presence of a catalyst and then conversion of nitrile functions to amino functions in the presence of a hydrogenation catalyst to obtain amines. For example US 2,526,044 describes (column 4 line 62) that polynitriles obtained from castor oil dehydrated in the presence of phosphorus can be hydrogenated to polyamines using nickel or platinum catalysts. But beforehand, the polynitrile must be distilled despite a very high boiling point.

US 3,010,782 describes (column 1, line 40) the synthesis of polynitriles from octadecadienoic acid and ammonia which can then be hydrogenated to polyamines but without specifying their degree of purity.

No. 3,231,545 discloses (column 2, line 61) that dimeric fatty acids can be converted to the corresponding nitriles and then hydrogenated to diamines. In addition, it is specified that purification is necessary at each step in order to obtain diamines of good purity for use in the field of polymers.

These same indications are given in US 3,242,141, US 3,483,237; in the latter patent, it is further specified (column 5, line 74) that the hydrogenation as described leads to a diamine having a high level of secondary and tertiary amine. The need to purify the products from each of the steps is also mentioned in US 3,475,406 where it is specified that these diamines must be purified by distillation so that the level of impurities is less than 10% and preferably less than 5% (column 5, line 35).

The teaching of all these patents is that it is necessary to purify the nitriles before their conversion into amines and / or that it is necessary to purify the amines at the end of the two-step process by distillation, which is particularly important. difficult given the boiling point of these products.

DESCRIPTION OF THE INVENTION

The present invention firstly proposes a method of synthesis, by hydrogenation of di- and / or tri-amines of high purity from di- or tri-nitriles (also hereinafter referred to as "nitriles"). The di- and / or tri-nitriles used may be in particular mixtures of dimerization and / or trimerization products of mono-nitriles comprising generally 8 to 30 carbon atoms, and one or more unsaturations, mainly in the form of double bond (s), which allow said dimerization and / or trimerization. This step of hydrogenation of the nitriles to primary amines takes place in a reactor under pressure, for example in an autoclave, in the presence of a hydrogenation catalyst, ammonia and optionally at least one strong base. The nitriles and the hydrogenation catalyst, such as, for example, Raney nickel, Raney cobalt, palladium or rhodium supported on carbon or alumina are charged into the reactor which is then purged with nitrogen.

The ammonia is then introduced at room temperature so as to create a partial pressure of ammonia and the reaction medium is stirred at a temperature between 100 ⁰ C and 130 ⁰ C before introducing hydrogen. The temperature of the reaction is generally comprised, in the broad sense, between 110 ° C. and 170 ^° C., and preferably from 130 ^° C. to 150 ^° C.

The amount of hydrogenation catalyst used represents from 0.1% to 15%, preferably from 3% to 10% by weight of the nitrile feedstock and more preferably from 4% to 8%. - AT -

The total pressure of the reactor during this step is generally between 2 MPa and 4 MPa, but one could operate at higher pressure (15 MPa) without inconvenience and without departing from the scope of the invention.

The reaction can be carried out in a solvent medium, the solvent being chosen from the conventional solvents used for this type of reaction.

According to an advantageous embodiment, the reaction is conducted in the absence of a solvent, especially in the case where the starting polynitriles are in liquid form. The reaction is continued in this way until the hydrogen consumption stops and the measurement of the alkalinity index no longer varies.

In the context of the present invention, the molar ratio ammonia / nitrile functions is between 0.2 and 3. By molar ratio ammonia / nitrile functions is meant the ratio between the number of moles of ammonia introduced and the number of functions. nitriles present in the reaction medium.

The number of nitrile functions present in the reaction medium can be determined by any quantitative analysis method known to those skilled in the art and for example by quantitative analysis by infrared spectrometry.

When the polynitrile involved in the hydrogenation reaction comes from a mixture of fatty acids as indicated above, it may be envisaged to determine the number of acid functions according to techniques known to those skilled in the art. The number of nitrile functions generated during the ammoniation reaction described below can then be understood as being equal to the number of transformed acid functions.

It has been surprisingly discovered, and it is what forms one of the aspects of the present invention, that the addition of a relatively small amount of base, in the reaction medium of hydrogenation of the nitrile functions in amino functions, significantly reduces the amount of ammonia introduced, while maintaining the selectivity that would be obtained with a larger amount of ammonia. The base which may be added to the reaction medium may be of any type, and in particular a strong base, organic or inorganic, preferably mineral, in particular chosen from alkali metal or alkaline earth metal hydroxides, for example hydroxide hydroxide. sodium or potassium hydroxide. It is particularly preferred to use sodium hydroxide. A mixture of two or more bases may also be used.

Thus, when the molar ratio ammonia / nitrile functions is between 0.2 and 1, 3, and preferably between 0.5 and 1, at least one strong base, such as sodium hydroxide and / or hydroxide potassium is added to the reaction mixture in a proportion of 0.07% to 1% by mole, and preferably from 0.35% to 0.75% by mole, relative to the number of nitrile functions present in the reaction medium and such that defined it above. The at least one strong base is preferably added in aqueous form. It should be understood that when the molar ratio ammonia / nitrile functions is between 1, 3 and 3, and preferably between 1, 5 and 2.6, one can overcome the presence of strong base.

The hydrogenation step of the process according to the invention makes it possible to convert the nitrile functions to 100% primary amine functions with a selectivity greater than 97% of primary amines, which makes it possible to use diamines and triamines directly and without purification. in applications where the required purity is very important.

The polynitriles, in particular di- and tri-nitriles used in the process for the preparation of primary amines, principally in the form of diamines and triamines, can advantageously be obtained from di- and / or tri-fatty acids. mothers, according to conventional ammoniation techniques known to those skilled in the art.

The ammoniation reaction may for example be carried out in the conventional manner in the presence of an ammoniation catalyst preferably chosen from metal oxides, and preferably zinc oxide, in a weight ratio of catalyst / diacids and / or triacids. between 0.01% and 0.15% and preferably 0.03% and 0.1%. The reaction medium is stirred and heated to a temperature generally ranging from 150 ^° C. to 170 ^° C., followed by ammonia. gaseous is introduced into the reactor, for example by means of a diving rod, and the temperature is increased, preferably in steps, at a temperature generally ranging from 250 ^° C. to 320 ^° C., preferably from 290 ^° C. to 310 ^° C. ⁰ C. the pressure is generally between 0.05 MPa and 0.4 MPa, to atmospheric pressure (0.1 MPa) being preferred. The water formed and the excess ammonia may be collected in a trap via a dephlegmator maintained at 130 ⁰ C. The reaction is continued until the acid value of the reaction medium is less than or equal to 0.1 mg KOH / g, for a duration of 12 to 17 hours. Infrared and mass spectroscopy analyzes show that the acid functions are almost quantitatively transformed into nitriles.

As for the hydrogenation reaction described above, the ammoniation reaction can be carried out in a solvent medium. However, it is preferred to carry out the conversion of the acid functions to nitrile functions in the absence of a solvent, especially when the compounds carrying the acid functions are used in the liquid state.

The nitriles thus obtained can be used as such, that is to say without intermediate purification, for the hydrogenation reaction described above to form the di- and tri-amines.

In another aspect, the present invention provides a process for synthesizing high purity di- and / or tri-amines from di- and / or trimer fatty acids in two steps which does not require any purification step, comprising the following steps: N in a reactor under stirring, conversion of the acid functional groups of the dimer and / or trimeric acids to nitriles to give di- and tri-nitriles in the presence of an ammoniation catalyst preferably chosen from oxides metal, and preferably zinc oxide, in a catalyst / diacid and / or triacid weight ratio of between 0.01% and 0.15%, then introduction of gaseous ammonia into the reactor,

B / in a reactor under pressure, conversion of the nitrile functions of the product resulting from stage A / into primary amines by implementation of the process described above, that is to say by hydrogenation, in the presence of a hydrogenation catalyst and hydrogen, conversion in which,

• after contacting nitriles and hydrogenation catalyst are introduced ammonia at room temperature and the reaction medium is stirred before introducing the hydrogen, the reaction temperature from 110 ⁰ C to 170 ⁰ C and preferably from 130 ° C. to 150 ^° C.,

The amount of hydrogenation catalyst used represents from 0.1% to 15% by weight of the nitrile feedstock, and the molar ratio of ammonia to nitrile functions is between 0.2 and 3.

In the ^1st step (step A), converting the acid functions of dimer acids and / or trimers of nitrile function to obtain di- and tri-nitriles

(Ammoniation reaction described above) and in the second step (step B), the nitrile functions are converted to primary amino function by hydrogenation, as indicated above.

In particular, the process of the invention can be advantageously used for the preparation of primary amines, in the form of di- and / or tri-amines of high purity, with a high selectivity. By "high selectivity" it is meant that the nitrile functions are converted into primary amine functions, in particular more than 95% transformed into primary amine functions, with respect to the total number of amine functions formed, more specifically to more than 97% in functions. primary amines. The other amine functions formed may be predominantly secondary amines, for example in proportions of less than 5%, preferably less than 3%, relative to the total number of amine functions formed. As for tertiary amines, if they are formed, they are generally only in trace amounts.

The process of the present invention finds a particularly advantageous application in the selective synthesis of primary di- and / or tri-amines, with high selectivity, from unsaturated fatty acids from tall oil or other vegetable sources. and which are mainly in the form of di- and / or trimers. Of such acidic forms are well known and described for example in US Pat. No. 3,475,406 or patent application WO 2003/054092.

The process for synthesizing primary di- and / or tri-amines from unsaturated fatty acids can be represented according to the following scheme:

ammoniated

hydrogenation

scheme in which only diacids, dinitriles and diamines are represented and where a, b, c and d represent independently of each other the number of methylene links (-CH ₂ -) on each of the chains. Generally, a, b, c and d are each between 1 and 24, more generally between 2 and 20, more particularly between 4 and 16.

Because of their high purity and their high selectivity (> 95% primary amines), the primary amines obtained according to the process of the present invention find applications in very many fields. AT Examples of use of these amines include their use as anti-corrosion agents, in the detergency, as additives for bitumen, flotation agents, anti-mottants, anti-dust, crosslinking agents, petroleum additives, lubricating agents, water treatment additives, concrete additives, and others.

The following examples are provided by way of illustration of the present invention without limiting the scope of the protection defined by the claims appended to this description.

Example 1 Synthesis of a dinitrile ex Pripol 1013

In a previously dried 3 L glass reactor equipped with a mechanical stirrer, an electric heater, a dephlegmator, a refrigerant and a dry ice trap, an introduction system of ammonia, 2,516 g of dimerized fatty acid, marketed under the name Pripol 1013, having an acid number of 191.9 mg KOH / g are charged. A catalytic charge of zinc oxide of 1. 57 g is added, ie 0.0625% of the weight of dimerized fatty acid used. The reaction medium is stirred and then heated to 160 ^° C. Then the ammonia gas is introduced at a rate of 0.417 L / min.kg. The reaction medium is brought to 300 ^° C. The introduction of ammonia is continued until the acid number of the reaction medium is less than 0.1 mg of KOH / g. The reaction time is about 12 to 14 hours. At the end of the reaction, the reaction medium is cooled to 40 ^° C. and the reactor is emptied. The yield is close to 100% and the selectivity is almost complete in dinitrile.

Example 2 Synthesis of a dinitrile ex Pripol 1048

In a setup identical to that of Example 1, 2.130 g of dimer / trimer fatty acid marketed under the name Pripol 1048 (mixture of dimer acid and hydrogenated trimer) having an acid number of 187.8 mg are charged. of KOH / g. A catalytic charge of zinc oxide of 1.33 g is added, ie 0.0625% of the weight of fatty acid used. The reaction medium is stirred and then heated to 160 ^° C. Then the ammonia gas is introduced at a rate of 0.417 L / min.kg. The reaction medium is brought to 300 ^° C. The introduction ammonia is continued until the acid number of the reaction medium is less than 0.1 mg KOH / g. The reaction time is 15 hours. At the end of the reaction, the reaction medium is cooled to 40 ^° C. and the reactor is emptied. The yield is close to 100% and the selectivity is almost total in nitrile function.

Example 3 Synthesis of a diamine ex Pripol 1013

In a 500 cm ³ autoclave, 200 g of dinitrile from Example 1 (Pripol 1013) and 15 g of Raney nickel, which has been drained and washed with isopropanol, are charged with 7.5% by weight of the initial charge. dinitrile. The reactor is closed under pressure, the tightness is checked and the nitrogen is inerted by compression / decompression. The ammonia gas is then introduced at room temperature, which gives a pressure of 0.5 to 0.6 MPa at 25 ^° C. This corresponds in this case to a weight of approximately 25 to 35 g of anhydrous ammonia. The reaction medium is brought to 120-130 ^° C. with stirring and the hydrogen is then introduced to have a total pressure of 2.3 to 2.5 MPa. Hydrogen consumption is immediate. Monitoring is provided by measuring the alkalinity as the reaction progresses. This lasts around 10 am. At the end of the reaction, the reaction medium is cooled to ambient temperature, the hydrogen and ammonia are purged with nitrogen, and the crude reaction product is drained. The catalyst is recovered by filtration under nitrogen and the latter can be recycled. The conversion of the nitrile is 100% and the content of secondary amines is less than 3% (limit of quantification by NMR).

EXAMPLE 4 Synthesis of a diamine ex Pripol 1048 In a 500 cm ³ autoclave, 200 g of nitrile from Example 2 are charged.

(ex Pripol 1048) and 15 g of Raney Nickel drained and washed with isopropanol is 7.5% by weight of the initial charge of nitrile ex Pripol 1048. The reactor is closed under pressure, the tightness is checked and performs nitrogen inerting by compression / decompression. The ammonia gas is then introduced at room temperature, which gives a pressure of 0.6 MPa at 25 ^° C. The reaction medium is brought to 120-130 ^° C. with stirring, then the hydrogen is introduced to have a total pressure of 2.5 MPa. Hydrogen consumption is immediate. Monitoring is ensured by measuring the alkalinity as and when the progress of the reaction. This one lasts 12 hours. At the end of the reaction, the reaction medium is cooled to ambient temperature, the hydrogen and ammonia are purged with nitrogen, and the crude reaction product is drained. The catalyst is recovered by filtration under nitrogen and the latter can be recycled. The conversion of the nitrile is 100% and the content of secondary amines is less than 3% (limit of quantification by NMR).

Examples 5 to 12 Synthesis of diamines ex Pripol 1013

Other amines were synthesized from dinitrile ex Pripol 1013 of Example 1; the second step was conducted with operating conditions different from those of Examples 3 or 4 above (rate and type of catalyst, partial pressure of ammonia, possible presence of water in the catalyst, optional addition of strong base). The operating conditions of the examples

5 to 12 as well as the characteristics of the diamines synthesized are detailed in the table below:

Claims

A process for synthesizing di- and / or triamines from di- or tri-nitriles comprising the step of converting nitrile functions to primary amine functions by hydrogenation, in the presence of a hydrogenation and hydrogenation catalyst , characterized in that, after bringing the nitriles and the hydrogenation catalyst into contact, the ammonia is introduced at room temperature and the reaction medium is stirred before introducing the hydrogen, the reaction temperature ranging from from 110 ^° C. to 170 ^° C. and preferably from 130 ^° C. to 150 ^° C.,

In that the amount of hydrogenation catalyst used represents from 0.1% to 15% by weight of the nitrile feed, and

In that the molar ratio ammonia / nitrile functions is between 0.2 and 3.

2. Method according to claim 1, wherein when the molar ratio ammonia / nitrile functions is between 0.2 and 1, 3, and preferably between 0.5 and 1, is added to the reaction medium at least one strong base, preferably in aqueous form, in a proportion of from 0.07 to 1 mol%, preferably from

0.35 to 0.75 mol%, relative to the nitrile functions.

3. The method of claim 1, wherein, when the molar ratio ammonia / nitrile functions is between 1, 3 and 3, and preferably between 1, 5 and 2.6, the presence of strong base is optional.

4. Method according to any one of claims 1 to 3, wherein the reaction is carried out at a total pressure of between 2 MPa and 15 MPa, preferably between 2 MPa and 4 MPa.

5. Process according to any one of the preceding claims, in which the amount of hydrogenation catalyst used represents 3% to 10% by weight of the nitrile feedstock, and in that the molar ratio of ammonia / nitrile functions is included. between 0.5 and 1.

6. Method according to any one of the preceding claims, characterized in that the amount of hydrogenation catalyst used is 4% to 8% by weight of the nitrile feedstock and in that the molar ratio of ammonia / nitrile functions is between 1, 5 and 2.6.

7. Method according to one of the preceding claims, characterized in that the hydrogenation catalyst is selected from Raney Nickel, Raney Cobalt, Palladium and / or or Rhodium supported on carbon, and alumina.

8. A process for synthesizing di- and / or triamines from di- and / or trimeric fatty acids comprising the following steps:

A / in a stirred reactor, conversion of the acid functional groups of dimer and / or trimeric acids to nitriles to give di- and tri-nitriles in the presence of an ammoniation catalyst preferably chosen from metal oxides, and preferably zinc oxide, in a catalyst / diacid and / or triacid weight ratio of between 0.01% and 0.15%, and then introduction of gaseous ammonia into the reactor,

B / in a reactor under pressure, conversion of the nitrile functions of the product resulting from stage A / into primary amines by carrying out the process according to any one of claims 1 to 7.

9. Process according to claim 8, characterized in that step A / is carried out at a pressure of between 0.05 and 0.4 MPa, the atmospheric pressure (0.1 MPa) being preferred, at a temperature ranging from 150 ⁰ C at 170 ⁰ C before introduction of NH3, then the temperature is increased, preferably in steps, at a temperature ranging from 250 ⁰ C to 320 ⁰ C, preferably from 290 ⁰ C to 310 ⁰ C.

10. The method of claim 8 or claim 9, characterized in that in step A /, the catalyst / diacid and / or triacid weight ratio is between 0.03% and 0.1%.

11. Di- and tri-amines obtainable by the process as defined in claims 1 to 10.