WO2013121151A1

WO2013121151A1 - Process for synthesizing dinitrile, diamine and polymer from acid disalt

Info

Publication number: WO2013121151A1
Application number: PCT/FR2013/050301
Authority: WO
Inventors: Jean-Luc Dubois; Antoine Piccirilli; Julien Magne; Sabrina Tricoire
Original assignee: Arkema France
Priority date: 2012-02-14
Filing date: 2013-02-14
Publication date: 2013-08-22
Also published as: FR2986793B1; FR2986793A1

Abstract

The present invention relates to a process for producing dinitrile, characterized in that it comprises at least one step of reaction between a sodium disalt of a diacid and an ammonia source, under the following conditions: - the ammonia source/disalt molar ratio is included in the range of from 1 to 20, - the reaction temperature is included in the range of from 200 to 350°C, - the reaction pressure is included in the range of from 0.1 to 20 MPa. This process comprises a step of ammoniation of the acid disalt functions and does not require any step(s) of intermediate hydrolysis of the disalt to give acid. The subject matter of the present invention is also the production of diamine, said process also comprising a step of hydrogenation of the nitrile functions to give primary amine functions.

Description

PROCESS FOR THE SYNTHESIS OF DINITRILE, DIAMINE AND POLYMER

FROM DI-SALT OF ACID

TECHNICAL AREA

The present invention relates to a process for synthesizing dinitrile from a di-salt diacid. Dinitriles are used in particular to produce diamines, likely to be in the composition of many polymers, such as polyamides.

STATE OF THE PRIOR ART

In current processes, the di-acid di-salt is not usable as such. It is the diacid, isolated and recovered from di-salt by double washing with sulfuric acid and recrystallization, which finds many applications. By way of example, sebacic acid or decanedioic acid of formula HOOC (CH ₂ ) ₈ COOH serves in particular to form decane diamine (C 10 diamine) by a two-step process: conversion of carboxylic functions to nitrile functions by action ammonia in the presence of a catalyst (usually zinc oxide), then conversion of nitrile functions to amino functions in the presence of a hydrogenation catalyst (eg Raney nickel) to obtain a diamine. The diamine forms with a diacid a monomer used in polyamides.

The major advantage of this diamine formed from sebacic acid lies in the fact that it is derived from vegetable raw material and therefore renewable. Indeed, the sodium di-salt of sebacic acid is obtained by "basic cracking" or "alkaline pyrolysis" or decomposition at 250 ° C in the presence of sodium hydroxide, acid or ricinoleic ester, itself derived from castor oil. During this basic cracking, a succession of reactions take place simultaneously. The first is a dehydrogenation (hydrogen transfer) of the hydroxyl group to give a ketone, then an isomerization of the C = C double bond, followed by a hydration of this double bond, itself followed by a reaction of retro -aldolisation. At this stage, 2-octanone and an aldehyde-acid (salt) with 10 carbon atoms should be obtained. As the hydrogen transfer reactions continue, it is in fact 2-octanol which distils from the reaction medium. The reaction is carried out hot and in the presence of soda, a reaction redox type is set up and the aldehyde-acid (salt) is oxidized to diacid or more exactly di-sodium diacid. In these processes, the di-salt of sebacic acid, to be converted to the corresponding diacid, is hydrolysed in the presence of sulfuric acid to give on the one hand sebacic acid recovered by cold recrystallization (room temperature of 15%). at 25 ° C) and on the other hand polluting, corrosive and irritating salts. This acid hydrolysis process is long, complicated, expensive in energy and polluting, in particular because of the large volumes of discharges related to the neutralization of salts, the process producing a large amount of ammonium sulfate.

By targeting the diamines, it is sought to completely reconsider this process, in particular by avoiding having to isolate the diacid.

The present invention therefore aims to find a simpler process for producing diamine of renewable origin, which has the least possible steps and does not require acid hydrolysis step or expensive crystallization step in energy or polluting.

The Applicant has now found a new process which makes it possible to dispense with the step of purifying the diacids by allowing the direct manufacture of dinitrile precursors of diamines.

DESCRIPTION OF THE INVENTION

The subject of the present invention is therefore a novel process for producing dinitrile or even diamine, directly from the sodium di-salt of the corresponding diacid, that is to say of the same number of carbons.

The present invention more particularly relates to a process for producing dinitrile, characterized in that it comprises at least one reaction step between a di-sodium salt of diacid and a source of ammonia, under the following conditions:

the molar ratio source of ammonia / di-salt is in the range of 1 to 20, preferably from 1 to 10, preferably from 2 to 6,

the reaction temperature is in the range of 200 to 350 ° C, preferably in the range of 250 ° C to 325 ° C, the reaction pressure is in the range from 0.1 to 20 MPa, preferably from 0.1 to 10 MPa, preferably from 0.1 to 3 MPa, preferably from 0.1 to 1.5 MPa; ,

in the optional presence of an ammoniation catalyst, preferably ZnO, preferably in a content of 0 to 0.5%, preferably 0 to 0.2% by weight relative to the di-salt charge, and preferably without catalyst.

The dinitrile thus obtained is easily distillable, and its recovery does not require crystallization.

This new process for manufacturing dinitriles precursors of renewable diamines does not require passing through a diacid, so does not require associated purification step, hydrolysis or crystallization and does not have the aforementioned disadvantages. The dinitrile obtained is purified for example by simple distillation.

The di-salt of acid, more precisely the di-salt diacid, used in the process of the invention is preferably derived, in particular by alkaline fusion (also called decomposition or pyrolysis), acid or ester of renewable origin, preferably of a hydroxylated fatty acid or ester derived from oleaginous plants, preferably those with industrial and thus non-food uses, and comprising a radical - (CH 2 -CH = CH-CH ₂ -CHOH) - .

According to a particular embodiment of the process of the invention, the di-salts are obtained by alkaline fusion of said acids / esters in the presence of sodium NaOH, said melting comprising the following steps: dehydrogenation, isomerization, hydration, retroaldolization, redox reaction with soda so as to obtain a sodium di-salt of diacid and a ketone.

Advantageously, the hydroxylated fatty acid or ester is chosen from: the acid / ricinoleic ester (12-hydroxy-9-octadecenoic acid), the lesquerolic acid / ester (14-hydroxy-cis-11-eicosenoic acid), the densipolic acid / ester (12-hydroxy-9,15-octadecadienoic acid) and the acid / auricolic ester (14-hydroxy-1,1,17-eicosadienoic acid). The formulas of these fatty acids / esters are represented below:

Ricinoleic acid

Lesqueric acid

Densipolic acid

Auricolic acid

The preferred hydroxylated fatty acids are ricinoleic and lesquerolic acids, which respectively form C10 and C12 acid di-salts, which give C10 and C12 dinitriles according to the process of the invention, and then lead to C10 diamines. and C12 respectively. Similarly, Densipolic and Auricolic acids form di-salts which respectively give, according to the process of the invention, C10 and C12 dinitriles, then the corresponding C10 and C12 diamines, respectively.

Preferably, the di-salt used in the process of the invention is therefore chosen from:

sebacic acid di-salt (C 10 acid) derived especially from ricinoleic acid or densipolic acid; or

dodecanedioic acid di-salt (C12 acid) derived especially from lesquerolic acid or auricolic acid.

Preferably, the acid sodium di-salt used in the process of the invention is in molten form to improve its reactivity with the ammonium source.

The initial di-salt may in particular be in the form of a crude product resulting from pyrolysis, that is to say in a mixture with other products (co-products), such as the sodium salts of oleic acid, stearic acid, palmitic acid and linoleic acid, which do not react during the process according to the invention. These coproducts are found in mixture with the dinitrile obtained, in whole or in part in the form of fatty nitrile and their separation is by simple distillation and / or extraction with solvent at the end of the process according to the invention.

The source of ammonia used can be chosen in particular from ammonia, ammonium sulphate - which also makes it possible to recover or recycle ammonium sulphate, the waste of many industries - ammonium carbonate , urea, their mixtures, and any other source of available ammonia. Ammonium sulphate is an advantageous source of ammonia for displacing reactions by forming sodium sulphate (or potassium when the alkaline fusion has been carried out with potassium hydroxide). Preferably, ammonia will be used, which makes it possible to envisage a recycling of the sodium hydroxide in the upstream stages of the process. Urea and ammonium carbonate are also Useful ammonia sources, the reaction being displaced by the formation of sodium carbonate which is easily recovered and recycled in the process.

Advantageously, the source of ammonia is in the form of crushed granules to facilitate their reaction in the molten salt medium. This ground form allows a better meltability and better reactivity of the ammonia source with di-diacid salt, the reaction medium is more homogeneous.

In the context of the present invention, the molar ratio source of ammonia / di-salt is in the range of 1 to 20, preferably from 1 to 10, preferably from 2 to 6. By molar ratio source of ammonia di-salt means the ratio between the number of moles of the source of ammonia introduced and the number of moles of di-salt present in the reaction medium. The number of moles of di-salt present in the reaction medium may be determined by any quantitative analysis method known to those skilled in the art, in particular by quantitative analysis by infrared spectrometry, by gravimetry, by elemental analysis (sodium content and / or carbon content).

The reaction is optionally carried out in the presence of a catalyst, such as ZnO. The amount of nitrilation catalyst (or "ammoniation", qualifying a nitrilation reaction that involves ammonia) used is 0% to 0.5%, preferably 0% to 0.2% by weight of the di-salt charge. But preferably, the method of the invention does not use a catalyst. The heterogeneous catalyst in the reaction carried out is found at the end of the reaction in mixture with unreacted fatty acid salts.

The total reactor pressure during this reaction is generally in the range of 0.1 to 20.0 MPa, preferably 0.1 to 10.0 MPa, but it would be possible to operate at higher pressure without inconvenience and without depart from the scope of the invention.

The reaction may be carried out in a solvent medium, the solvent being chosen from the conventional solvents used for this type of reaction, such as diphenyl ethers, aryl-arylenes or diarylarylenes such as Jarytherm, heavy paraffins (more than 20 carbon atoms per molecule), nitroalkanes (with more than 10 carbon atoms), alkyl sulphoxides (with more than 2 carbon atoms), sulpholane, nitrobenzenes, fatty mono- and di-nitriles, alkyls naphthalenes. Preferably, the reaction is conducted in the absence of a solvent, since the solvents tend to degrade at the high temperatures necessary for the process of the invention.

The transformation reaction of acid di-salt into dinitrile is preferably carried out in a reactor under pressure, for example in an autoclave, with stirring, in the presence or absence of a catalyst. The di-salt, and any catalyst, is (are) charged to the reactor which is then purged with nitrogen.

In a batch mode of operation, the source of solid ammonia is introduced at room temperature so as to create a partial pressure of ammonia and the reaction medium is stirred at a temperature between 200 ° C and 350 ° C. The temperature of the reaction is generally in the range of 250 ° C to 325 ° C. When the source of ammonia is gaseous ammonia, the source of ammonia can be introduced at a temperature in the range of room temperature (15-25 ° C) to the reaction temperature, and throughout of the reaction. Preferably the source of ammonia is introduced from the moment the sodium salt is melted.

Advantageously, the reaction is carried out under an ammonia flow and / or with stirring and / or for a period of between 1 hour and 8 hours.

The reaction is continued in this way until ammonia consumption ceases. In batch mode, when the source of ammonia is a solid introduced at ambient temperature, the production of ammonia is characterized by an increase in the total pressure and the consumption of ammonia is characterized by a decrease in pressure. The reaction is continued until the pressure no longer changes significantly.

Preferably, the reaction is carried out continuously in a pressurized reactor which allows a continuous distillation of the dinitrile as it is produced. In continuous mode, when the source of ammonia is preferably gaseous ammonia or a source of solid ammonia. The dinitrile has a boiling point much lower than the corresponding diacid. Therefore, the dinitrile formed is preferably extracted, especially by distillation, continuously, this for two reasons, firstly to control the progress of the reaction, on the other hand to avoid possible degradation in the presence of the reaction co-products (water, carbonate, phosphate or sulfate, soda).

Advantageously, the sodium or potassium salt (sulfate, phosphate, carbonate, etc.) formed is eliminated in parallel as it is formed.

The nitriles obtained according to the process of the invention can be used as such, that is to say without intermediate purification, to form diamines by hydrogenation.

According to an advantageous embodiment, the process according to the invention therefore also comprises a step of synthesizing diamine from dinitrile comprising the conversion of the nitrile functions into primary amine functions by hydrogenation, in the presence of a hydrogenation catalyst and of dihydrogen and ammonia, characterized in that

after bringing the nitriles and the hydrogenation catalyst into contact, ammonia is introduced at ambient temperature and the reaction mixture is stirred while introducing the dihydrogen, the reaction temperature ranging from 1 ° C. to 170 ° C. ° 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 charge, and

the molar ratio ammonia / nitrile functions is in the range from 0.2 to 3.

Preferably, when the molar ratio ammonia / nitrile functions is in the range from 0.2 to 1, 3, and preferably from 0.5 to 1, is added to the reaction medium at least one strong base, preferably in the form of aqueous, at a rate of 0.07 to 1 mol%, preferably from 0.35 to 0.75 mol%, relative to the nitrile functions. Preferably, when the molar ratio ammonia / nitrile functions is in the range of 1, 3 to 3, and preferably from 1, 5 to 2.6, the presence of strong base is optional.

Advantageously, the hydrogenation reaction is carried out at a total pressure of between 2 MPa and 15 MPa, preferably between 2 MPa and 4 MPa (ie 40 bar). The hydrogenation catalyst is preferably chosen from: Raney nickel, Raney cobalt, Ruthenium, palladium and / or Rhodium supported on charcoal, copper chromites, silicon carbide and alumina.

The hydrogenation stage 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 decane diamine directly and without purification in the applications where the required purity is very important.

The subject of the present invention is therefore also a process for the synthesis of high purity diamine from di-salt of diacid in two stages, which does not require any purification step, comprising the following steps:

- in a ^1st step (step A), the di-salt of acid functions are converted into nitriles function to obtain dinitriles (ammoniation reaction or nitrilation described above), and

in the second step (step B), the nitrile functions are converted to primary amine function by hydrogenation, as indicated above.

The present invention also relates to a process for the synthesis of diamines from hydroxylated acids / fatty esters comprising a radical - (CH ₂ -CH = CH-CH ₂ -CHOH) -, comprising the following steps:

O / alkaline fusion in the presence of sodium hydroxide NaOH or potassium hydroxide hydroxylated fatty acids / esters, said fusion comprising the following steps: dehydrogenation, isomerization, hydration, (cut by) retroaldolization, oxidation reaction with sodium hydroxide / potash, so obtaining a di-sodium salt of diacid and a ketone (2-octanone) and / or an alcohol (2-octanol);

In a reactor under stirring, di-salt di-salt functions conversion to nitrile functions to obtain the corresponding di-nitrile by carrying out the process according to the invention;

B / in a reactor under pressure, conversion of the nitrile functions of the product resulting from step A / into primary amines by carrying out the hydrogenation process as described above.

In particular, the process of the invention can be advantageously used for the preparation of diamines, in particular of decane diamine or dodecanediamine of renewable origin, of high purity, with a high selectivity. By "high selectivity" it is meant that the nitrile functions are transformed 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% of primary amine functions.

Because of their high purity and their high selectivity (> 95% of primary amines), the primary amines obtained according to the method of the present invention find applications in a very large number of fields, and are especially used for the manufacture of polymers. , in particular those based on polyamide (PA) comprising monomers of "diamine.diacid" type, such as (PA (diamine). (diacid)) PA10.10, PA10.12, PA10.6, PA10.4 , PA12.12, PA6.12, PA4.12

By way of example of the use of these diamines, mention may also be made of their use as anti-corrosion agents, detergents, in polyurethanes, as additives in coatings and inks, in the manufacture of copolymers, as crosslinking agents. and chain extenders, as ingredients for pharmaceutical applications, ingredients for elastomers, as bitumen additives, flotation agents, anti-caking agents, dust suppressants, crosslinking agents, petroleum additives, lubricating agents, water treatment additives, additives for concrete.

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

Comparative 1: Synthesis of a C10 dinitrile

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 sebacic acid are charged. A catalytic charge of zinc oxide of 1. 57 g is added, ie 0.0625% of the weight of the diacid used. The reaction medium is stirred and then heated to 160 ° C. Then ammonia gas is introduced at a rate of 0.417 L / min.kg. The reaction medium is heated to 300 ° C. The introduction of ammonia continues until the acid number of the reaction medium is less than 0.1 mg 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.

Examples according to the invention

The tests were carried out in autoclave - batch mode - by mixing a known mass of sodium sebacate (sebacic acid disel) and a known mass of urea. If necessary, a catalyst (powdery zinc oxide) is added. The solid mixture is homogenized in the autoclave.

The synthesis is carried out in a closed reactor after purging with nitrogen to remove traces of oxygen. The parameter imposed during the tests is the temperature and the duration. During the reaction, the maximum pressure reached by the autoclave is recorded.

At the end of the reaction, the mass of product formed is noted. The product obtained is extracted and purified according to the following protocol:

Operating mode:

1) accurately weigh to the nearest 0.1 g 10 g of the reaction mixture in a beaker of 100 ml

2) add 50 ml of demineralized water in order to liquefy the reaction medium and dissolve all the salts formed (if necessary use the ultrasonic bath) and pour this mixture into a 250 ml ampoule

3) Add 50ml of diethyl ether to the 100ml beaker to rinse and pour 50ml into the separating funnel

4) Shake the ampoule and allow to settle

5) The heavy phase is then washed in the same way twice with 50 ml of diethyl ether

6) The three ether phases are then combined in a 250 ml separating funnel and washed until neutral with 50 ml of demineralised water. 3 washes are made.

7) The ether phase washed and decanted and then evaporated at 90 ° C. under 20 mbar

8) The dry extract obtained is then weighed and analyzed by GPC.

The operating conditions of Examples A4 to A17 and Comparative A16 are detailed in Table 1 below: Table 1

Comments:

A6: In the absence of ZnO and when the urea is finely ground before reaction, the yield is higher (15%) than the reaction carried out in the presence of ZnO and ball urea. This result confirms that the packaging of urea is an important parameter, the powder form providing a better meltability and, in fact, a better reactivity within a more homogeneous reaction medium;

A9: In the presence of ZnO and urea powder, the yield of dinitrile (DN) is decreased compared to the reaction carried out in the presence of ball urea A4. A10: At 325 ° C., in the presence of an excess of urea, and after one hour of reaction, the yield of the reaction is high: 37%. This result indicates that the reaction is rapid under these conditions. A1 1: (repeat of test A10) After 5 hours of reaction, a slight drop in yield is observed, compared to test A10, which is explained by a subsequent decomposition of dinitrile under the conditions of synthesis. It is therefore desirable to operate continuously, or at least semi-continuous with gradual removal of the dinitrile formed.

A16-A17: The sebacic acid and urea beads were previously reduced to powder and intimately mixed (with additionally sodium sebacate in A17) before being introduced into the reactor.

A16 (Comparative 2): the yield of dinitrile obtained is of the order of 48%. As a reminder, in the presence of di-salt (A10) the highest yield was 37%, showing that the difference in reactivity between the diacid and the salt is not so important as one might have supposed.

A17: the yield of dinitrile obtained is of the order of 46%, that is to say substantially close to that obtained with less urea engaged.

Example 2 Synthesis of Decane Diamine

In a 500 cm ³ autoclave, 200 g of dinitrile and 15 g of Raney nickel are filtered off and washed with isopropanol or 7.5% by weight of the initial feed of 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 ambient temperature, which gives a pressure of 0.5 to 0.6 MPa at 25 ° C. This corresponds in this case to a weight of about 25 to 35 g of anhydrous ammonia. The reaction medium is brought to 120-130 ° C with stirring and then the hydrogen is 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).

Claims

Process for the production of dinitrile, characterized in that it comprises at least one reaction step between a di-sodium salt of diacid and a source of ammonia, under the following conditions:

the molar ratio source of ammonia / di-salt is in the range of 1 to 20,

the reaction temperature is in the range of 200 to 350 ° C,

the reaction pressure is in the range from 0.1 to 20 MPa.

2. Process according to claim 1, in which the di-salt is derived from a diacidic hydroxylated acid / fatty ester comprising a radical -CH ₂ -CH = CH-CH ₂ -CHOH-, preferably chosen from the acid / ricinoleic ester, acid / ester lesquerol, acid / ester densipolic and acid / ester auricolic.

3. The process according to claim 1, wherein the di-salt is preferably selected from sebacic acid di-salt or dodecanedioic acid di-salt.

4. Method according to any one of the preceding claims wherein the source of ammonia is selected from: urea, ammonium carbonate, ammonium sulfate, ammonia, and mixtures thereof.

5. Method according to any one of the preceding claims wherein the reaction is carried out in the presence of an ammoniation catalyst, such as ZnO, preferably in a content of 0 to 0.5%, preferably 0 to 0.2% by weight relative to the di-salt charge, preferably without catalyst.

6. Process according to any one of the preceding claims wherein the reaction is carried out continuously.

7. Process according to any one of the preceding claims, in which the dinitrile formed is continuously extracted from the reaction medium, preferably by distillation.

8. Process according to any one of the preceding claims, further comprising a step of synthesizing diamine from the resulting dinitrile, comprising the conversion of the nitrile functions into primary amine functions by hydrogenation, in the presence of a hydrogenation catalyst and of dihydrogen, characterized in that:

after bringing the nitriles and the hydrogenation catalyst into contact, ammonia is introduced at ambient temperature and the reaction mixture is stirred while introducing the dihydrogen, the reaction temperature ranging from 1 ° C. to 170 ° C. ° C,

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

the molar ratio ammonia / nitrile functions is in the range from 0.2 to 3.

9. The method of claim 8, wherein the hydrogenation reaction is carried out at a total pressure of between 2 MPa and 15 MPa, preferably between 2 MPa and 4 MPa.

10. Process according to any one of claims 8 or 9, characterized in that the hydrogenation catalyst is chosen from: Raney nickel, Raney cobalt, palladium and / or or Rhodium supported on carbon, and alumina.

11. Process for the synthesis of diamines from hydroxylated fatty acids / esters comprising a radical -CH ₂ -CH = CH-CH ₂ -CHOH-, said process comprising the following steps:

O / alkaline fusion of said acids / esters in the presence of sodium NaOH, said melting comprising the following steps: dehydrogenation, isomerization, hydration, retroaldolization, oxidation by reaction with sodium hydroxide (or potassium hydroxide), so as to obtain a di-salt of sodium (or potassium) diacid;

A / in a stirred reactor, converting di-di-salt functions to nitrile functions to obtain the corresponding di-nitrile by carrying out the process according to any one of claims 1 to 7; 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 method according to any one of claims 8 to 10.

12. Diamine obtainable by the process as defined by any one of claims 8 to 11.

13. Polymer, in particular polyamide, comprising at least one diamine according to claim 12.