PROCESS FOR PREPARING 3 AMINOMETHYL-3,5,5-TRIMETHYLCYCLOHEXYLAMINE

Abstract

Process for preparing isophoronediamine, characterized in that

A) isophoronenitrile is subjected directly in one stage to aminating hydrogenation to give isophoronediamine in the presence of ammonia, hydrogen, a hydrogenation catalyst and possibly further additions, and in the presence or absence of organic solvents; or

B) isophoronenitrile is first converted fully or partly in at least two or more than two stages to isophoronenitrile imine, and this isophoronenitrile imine is subjected to aminating hydrogenation to give isophoronediamine as a pure substance or in a mixture with other components and/or isophoronenitrile, in the presence of at least ammonia, hydrogen and a catalyst.

Claims

1. A process for preparing isophoronediamine, wherein A) isophoronenitrile is subjected directly in one stage to aminating hydrogenation to give isophoronediamine in the presence of ammonia, hydrogen, a hydrogenation catalyst and possibly further additions, and in the presence or absence of organic solvents; or B) isophoronenitrile is first converted fully or partly in at least two or more than two stages to isophoronenitrile imine, and this isophoronenitrile imine is subjected to aminating hydrogenation to give isophoronediamine as a pure substance or in a mixture with other components and/or isophoronenitrile, in the presence of at least ammonia, hydrogen and a catalyst; where the catalyst has the following properties: I. the catalyst has, after the activation, in its entirety, the following composition in per cent by weight (% by weight), where the proportions add up to 100% by weight, based on the metals present: cobalt: 55% to 95% by weight aluminium: 5% to 45% by weight chromium: 0% to 3% by weight nickel: 0% to 7% by weight and II. the catalyst is in the form of irregular particles as a granular material and, after the activation, has particle sizes of 1 to 8 millimetres (mm).

2. The process for preparing isophoronediamine according to claim 1, wherein I. the catalyst has, after the activation, in its entirety, the following composition in per cent by weight (% by weight), where the proportions add up to 100% by weight, based on the metals present: cobalt: 55% to 90% by weight aluminium: 5% to 44.5% by weight chromium: 0.5% to 5% by weight

3. The process for preparing isophoronediamine according to claim 1, wherein I. the catalyst has, after the activation, in its entirety, the following composition in per cent by weight (% by weight), where the proportions add up to 100% by weight, based on the metals present: cobalt: 55% to 88% by weight aluminium: 5% to 44.5% by weight nickel: 0.5% to 7% by weight

4. The process for preparing isophoronediamine according to claim 1, wherein I. the catalyst has, after the activation, in its entirety, the following composition in per cent by weight (% by weight), where the proportions add up to 100% by weight, based on the metals present: cobalt: 55% to 85% by weight aluminium: 5% to 43.5% by weight chromium: 0.5% to 3% by weight nickel: 1% to 7% by weight

5. The process for preparing isophoronediamine according to claim 1, wherein I. the catalyst has, after the activation, in its entirety, the following composition in per cent by weight (% by weight), where the proportions add up to 100% by weight, based on the metals present: cobalt: 57% to 84% by weight aluminium: 10% to 40% by weight chromium: 1% to 2% by weight nickel: 2% to 4% by weight

6. The process for preparing isophoronediamine according to claim 1, wherein the particle sizes of the catalyst, i.e. the granule particles, vary from 2.5 to 6 millimetres (mm), or the particle sizes of the catalyst, i.e. the granule particles, vary from 3 to 7 millimetres (mm), or the particle sizes of the catalyst, i.e. the granule particles, vary from 2 to 5 millimetres (mm).

7. The process for preparing isophoronediamine according to claim 1, wherein the catalyst is obtained by screening the granules produced.

8. The process for preparing isophoronediamine according to claim 7, wherein the catalyst is obtained by screening the granules produced, and the particle sizes of the catalyst, i.e. the granule particles, have a statistical distribution between 2.5 and 5.5 millimetres (mm), or the particle sizes of the catalyst, i.e. the granule particles, have a statistical distribution between 3.5 and 6.5 millimetres (mm), or the particle sizes of the catalyst, i.e. the granule particles, have a statistical distribution between 2 and 5 millimetres (mm), or the particle sizes of the catalyst, i.e. the granule particles, have a statistical distribution between 3 and 7 millimetres (mm), and where up to 10 per cent of the particles may also be outside said range of said lower limit or upper limit, but up to 10 per cent in each case may also be outside said range of said lower limit and upper limit.

9. The process for preparing isophoronediamine according to claim 1, wherein the catalyst has, after the activation, in its entirety, the following composition in per cent by weight (% by weight), where the proportions add up to 100% by weight, based on the metals present: cobalt: 57% to 84% by weight aluminium: 10% to 40% by weight chromium: 1% to 2% by weight nickel: 2% to 4% by weight and with particle sizes of the catalyst, i.e. the granule particles, having a statistical distribution between 2.5 and 5.5 millimetres (mm), or particle sizes of the catalyst, i.e. the granule particles, having a statistical distribution between 3.5 and 6.5 millimetres (mm), or particle sizes of the catalyst, i.e. the granule particles, having a statistical distribution between 2 and 5 millimetres (mm), or particle sizes of the catalyst, i.e. the granule particles, having a statistical distribution between 3 and 7 millimetres (mm), where up to 10 per cent of the particles may also be outside said range of said lower limit or upper limit, but up to 10 per cent in each case may also be outside said range of said lower limit and upper limit.

10. The process for preparing isophoronediamine according to claim 1, wherein the catalysts additionally comprise doping metals.

11. The process for preparing isophoronediamine according to claim 1, wherein the catalysts comprise modifiers, alkali metals and alkaline earth metals or compounds thereof, magnesium and lithium compounds.

12. The process for preparing isophoronediamine according to claim 1, wherein at least some of the isophoronenitrile imine used is converted in the first stage by reaction with ammonia in the presence or absence of an imination catalyst and/or of solvents to isophoronenitrile imine, the conversion of IPN to IPNI after the imination being greater than 80%.

13. The process for preparing isophoronediamine according to claim 1, wherein the first stage reaction product, as obtained or after a further treatment and/or addition of further ammonia, is subjected in the second stage to aminating hydrogenation over hydrogenation catalysts in the presence of at least ammonia and hydrogen and in the presence or absence of an organic solvent at a temperature of 20 to 150° C., and a pressure of 0.3 to 50 MPa.

14. The process for preparing isophoronediamine according to claim 1, wherein the conversion of IPN to IPDA is effected in three separate reaction spaces, IPN being converted to isophoronenitrile imine with excess ammonia over imination catalysts in the first reaction space at temperatures between 20 and 150° C. and pressures between 5 and 30 MPa, the reaction products formed being hydrogenated with hydrogen in the presence of excess ammonia over hydrogenation catalysts in the second reaction space at temperatures between 20 and 130° C. and pressures of 5 to 30 MPa, and the reaction products formed being hydrogenated over catalysts in the third reaction space at temperatures between 100 and 160° C. and pressures of 5 to 30 MPa.

15. The process for preparing isophoronediamine according to claim 1, wherein the imination reaction is effected in the presence of at least one imination catalyst.

16. The process for preparing isophoronediamine according to claim 1, wherein the imination of isophoronenitrile with liquid ammonia is conducted without addition of further solvent.

17. The process for preparing isophoronediamine according to claim 1, wherein between 1 and 500 mol, of ammonia is used per mole of IPN used in the imination stage.

18. The process for preparing isophoronediamine according to claim 1, wherein the imination is conducted in the presence of a suspension catalyst or fixed bed catalyst, of at least one fixed bed catalyst.

19. The process for preparing isophoronediamine according to claim 1, wherein IPN and ammonia in the imination are conducted continuously from the bottom upward through a reaction tube filled with imination catalyst.

20. The process for preparing isophoronediamine according to claim 1, wherein the hydrogen required for the hydrogenation is supplied to the reactor either in excess, or in such an amount that the hydrogen consumed by reaction and the portion of the hydrogen which leaves the reactor dissolved in the product stream is replenished.

21. The process for preparing isophoronediamine according to claim 1, wherein the hydrogenation is conducted in liquid ammonia as solvent, using between 1 and 500 mol, of ammonia per mole of IPN.

22. The process for preparing isophoronediamine according to claim 1, wherein the hydrogenation catalysts are first conditioned with ammonia before they are used in the hydrogenation.

23. The process for preparing isophoronediamine according to claim 1, wherein the hydrogenation is effected continuously in fixed bed reactors.

24. The process for preparing isophoronediamine according to claim 1, wherein the hydrogenation is conducted continuously in fixed bed reactors which are operated in trickle mode or liquid phase mode.

25. The process for preparing isophoronediamine according to claim 1, wherein the reaction mixture leaving the hydrogenation is purified in one or more stages, and the isophoronediamine is obtained.

26. The process for preparing isophoronediamine according to claim 1, wherein the reaction mixture leaving the hydrogenation is purified in two steps, with complete or partial removal particularly of hydrogen, inert gases, ammonia, low-boiling impurities and optionally water in one or more distillation columns in a first step, and complete or partial removal of further low-boiling impurities, water and high-boiling impurities in distillation columns in a second step, and the isophoronediamine is obtained.

27. A catalyst for preparation of isophoronediamine, where the catalyst has the following properties: I. the catalyst has, after the activation, in its entirety, the following composition in per cent by weight (% by weight), where the proportions add up to 100% by weight, based on the metals present: cobalt: 55% to 95% by weight aluminium: 5% to 45% by weight chromium: 0% to 3% by weight nickel: 0% to 7% by weight and II. the catalyst is in the form of irregular particles as a granular material and, after the activation, has particle sizes of 1 to 8 millimetres (mm).

28. (canceled)

Description

EXAMPLE

[0123] Production of the Catalyst, Cobalt Granules:

[0124] a) Production of the Alloy

[0125] The alloy is produced in an induction oven. This involves melting the metals in the appropriate amounts at 1500° C. The finished melt is cast to bars for further processing.

[0126] b) Production of the Granules

[0127] The alloy bars are precomminuted by means of a jaw crusher and ground further by means of a roll mill. A screening step gives the desired size distribution of the granules through the choice of the appropriate screens.

[0128] c) Activation of the Catalyst

[0129] The catalyst is activated in a standard glass laboratory apparatus, for example a beaker. An aqueous alkali (e.g. sodium hydroxide solution) was added to the granules while stirring. The granules are in a catalyst basket during the activation. An exothermic operation leaches a portion of the aluminium out of the alloy with formation of hydrogen and sodium aluminate solution. The concentration of the alkali used was 20% by weight and the reaction temperature was 90° C. The degree of activation was determined by the reaction time. After the activation, the catalyst is washed with water and then stored under water.

[0130] The catalyst used has, after the activation, in its entirety, the following composition in per cent by weight (% by weight), where the proportions add up to 100% by weight, based on the metals present:

[0131] cobalt: 75.9% by weight

[0132] aluminium: 20.0% by weight

[0133] chromium: 1.5% by weight

[0134] nickel: 2.6% by weight

[0135] A screen fraction was used with particle sizes of the catalyst, i.e. the granule particles, having a statistical distribution between 2.0 and 5.0 millimetres (mm), where up to 10 per cent of the particles may also be outside said range of said lower limit or upper limit, but up to 10 per cent in each case may also be outside said range of said lower limit and upper limit.

[0136] Preparation of IPDA with the Inventive Catalyst

[0137] The catalysts are tested for their catalytic efficacy in the preparation of 3-aminomethyl-3,5,5-trimethylcyclohexylamine (isophoronediamine, IPDA) from 3-cyano-3,5,5-trimethylcyclohexanone (isophoronenitrile, IPN) in a two-stage process.

[0138] In the first stage, isophoronenitrile is at least partly converted to 3-cyano-3,5,5-trimethylcyclohexane imine with ammonia in the presence of an imination catalyst and, in the second stage, subjected to aminating hydrogenation with hydrogen in the presence of ammonia over a hydrogenation catalyst at a temperature of 60-100° C. and a pressure of 250 bar. Each stage of the preparation is conducted in a separate reactor. However, the two reactors are connected in series and their temperatures are controlled individually.

[0139] The hydrogenation reactor is charged with 42 ml of the catalyst to be tested. The input solution of IPN (15% by weight) and ammonia (85% by weight) is pumped through the reaction tube from the top downward at a mass flow rate of 110 ml/h. The hydrogen is added separately, likewise from the top, at a volume flow rate of 40 l/h. The product liquid is collected in a collecting vessel beneath the reactor. The collected product mixture is analysed by gas chromatography for IPDA and corresponding secondary components. The results are listed in Table 1.

TABLE-US-00001 TABLE 1 Temperature IPDA yield/GC % Conversion/% 100° C.  98.1 99.5 80° C. 96.7 98.5 60° C. 92.1 93.1

[0140] Long-term Stability

[0141] In the first stage, isophoronenitrile is at least partly converted to 3-cyano-3,5,5-trimethylcyclohexane imine with ammonia in the presence of an imination catalyst and, in the second stage, subjected to aminating hydrogenation with hydrogen in the presence of ammonia over a hydrogenation catalyst at a temperature of 60° C. (inventive catalyst) or 100° C. (reference catalyst, supported compressed shaped cobalt body) and a pressure of 250 bar. Each stage of the preparation is conducted in a separate reactor. However, the two reactors are connected in series and their temperatures are controlled individually.

[0142] For the testing of long-term stability, the hydrogenation reactor is charged with 100 ml of the catalyst to be tested. The input solution of IPN (22% by weight) and ammonia (78% by weight) is pumped through the reaction tube from the top downward at a mass flow rate of 120 g/h. In addition, hydrogen is added, likewise from the top, at a volume flow rate of 50 l/h. The product liquid is collected in a collecting vessel beneath the reactor. The collected product mixture is analysed by gas chromatography for IPDA and corresponding secondary components. The results are shown in FIG. 1.

[0143] Inventive catalyst: cobalt granules of the composition as described above

[0144] Reference catalyst: supported compressed shaped cobalt catalyst bodies