PROCESS FOR PREPARATION OF DI- AND POLYAMINES OF THE DIPHENYLMETHANE SERIES
First Claim
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1. A process for preparing diamines and polyamines of the diphenylmethane series (MBA) by reaction of aniline (1) and formaldehyde (2) at a desired molar ratio of aniline (1) to formaldehyde (2) of A/Ftarget, which comprises the steps:
- Either according to a variant A)A.I) reacting aniline (1) and formaldehyde (2) in the absence of an acid catalyst (3) in a reactor to form an aminal, with aniline (1) and formaldehyde (2) being introduced into the reactor, and subsequent separation of the reaction mixture obtained into an aqueous phase and an organic animal-containing phase; and
A.II) reaction-of-reacting at least part of the organic, aminal-containing phase obtained in step A.I) with acid (3) in a reactor, with the aminal reacting to form diamines and polyamines of the diphenylmethane series;
wherein the following steps are carried out for start-up of the process and/or resumption of the process after an interruption of at least the step A.I);
A.I.1) introaniline (1) into the reactor of step A.I) at a mass flow rate m1 commencing at the point in time t0;
A.I.2) introducing of formaldehyde (2) into the reactor of step A.I), commencing at a point in time t1, starting from a mass flow rate m2=0 at the point in time t1 to a mass flow rate m2=m2,intended at the point in time t2, where t2>
t1>
t0; and
A.II.1) in the case of interruption of the step A.II) too, introducing acid (3) into the reactor of step A.II) at the latest when, as soon as or after, organic, animal-containing phase is introduced for the first time into the reactor of step A.II),where the introduction of aniline (1) in step A.I.1) and the introduction of formaldehyde (2) in step A.I.2) occur in such a way that the instantaneous molar ratio ofthe total aniline (1) introduced into the reactor of step A.I)tothe total formaldehyde (2) Introduced into the reactor of step A.I),A/Finst, is always ≧
2 and ≧
1.05·
A/Ftargets during the period of time t1 to t2;
or according to a variant B),B.I) reacting aniline (1) and acid (3) in a rector to form a reaction mixture containing the anilinium salt of the acid (3) used; and
B.II) reacting of at least part of the reaction mixture obtained in step B.I) with formaldehyde (2) in a reactor, forming diamines and polyamines of the diphenylmethane series;
wherein the following steps are carried out for the start-up of the process and/or the resumption of the process after an interruption of the steps B.I) and B.II);
B.I.1) introducing aniline (1) into the reactor of step B.I) at an aniline mass flow rate m1 commencing at the point in time t0;
B.I.2) introducing of acid (3) before, simultaneously with or after introduction of aniline (1);
B.II.1) introducing of formaldehyde (2) into the reactor of step B.II), optionally together with further aniline (1), optionally together with further acid (3), commencing at a point in time ti, proceeding from a mass flow rate m2=0 at the point in time t1 to a mass flow rate m2=m2,intended at the point in time t2, where t2>
t1>
t0;
where the introduction of aniline (1) in step B.I.1) and optionally in step all) and the introduction of formaldehyde (2) in step B.II.1) occur in such a way that the instantaneous molar ratio ofthe total aniline (1) introduced into the reactor of step B.I) and, if present, the total aniline (1) introduced into the reactor of step B.II)tothe total formaldehyde (2) introduced into the reactor of step B.II),A/Finst, is always ≧
2 and ≧
1.05 A/Ftarget during the period of time from t1 to t2.
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Abstract
The invention relates to a method for the preparation of di- and polyamines of the diphenylmethane series (MDA) from aniline and formaldehyde, care being taken during the start up that a sufficient excess of aniline with respect to formaldehyde is ensured, said excess amounting to at least 105% of the desired molar ratio of aniline to formaldehyde for the target recipe of the MDA to be produced.
3 Citations
12 Claims
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1. A process for preparing diamines and polyamines of the diphenylmethane series (MBA) by reaction of aniline (1) and formaldehyde (2) at a desired molar ratio of aniline (1) to formaldehyde (2) of A/Ftarget, which comprises the steps:
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Either according to a variant A) A.I) reacting aniline (1) and formaldehyde (2) in the absence of an acid catalyst (3) in a reactor to form an aminal, with aniline (1) and formaldehyde (2) being introduced into the reactor, and subsequent separation of the reaction mixture obtained into an aqueous phase and an organic animal-containing phase; and A.II) reaction-of-reacting at least part of the organic, aminal-containing phase obtained in step A.I) with acid (3) in a reactor, with the aminal reacting to form diamines and polyamines of the diphenylmethane series; wherein the following steps are carried out for start-up of the process and/or resumption of the process after an interruption of at least the step A.I); A.I.1) introaniline (1) into the reactor of step A.I) at a mass flow rate m1 commencing at the point in time t0; A.I.2) introducing of formaldehyde (2) into the reactor of step A.I), commencing at a point in time t1, starting from a mass flow rate m2=0 at the point in time t1 to a mass flow rate m2=m2,intended at the point in time t2, where t2>
t1>
t0; andA.II.1) in the case of interruption of the step A.II) too, introducing acid (3) into the reactor of step A.II) at the latest when, as soon as or after, organic, animal-containing phase is introduced for the first time into the reactor of step A.II), where the introduction of aniline (1) in step A.I.1) and the introduction of formaldehyde (2) in step A.I.2) occur in such a way that the instantaneous molar ratio of the total aniline (1) introduced into the reactor of step A.I) to the total formaldehyde (2) Introduced into the reactor of step A.I), A/Finst, is always ≧
2 and ≧
1.05·
A/Ftargets during the period of time t1 to t2;or according to a variant B), B.I) reacting aniline (1) and acid (3) in a rector to form a reaction mixture containing the anilinium salt of the acid (3) used; and B.II) reacting of at least part of the reaction mixture obtained in step B.I) with formaldehyde (2) in a reactor, forming diamines and polyamines of the diphenylmethane series; wherein the following steps are carried out for the start-up of the process and/or the resumption of the process after an interruption of the steps B.I) and B.II); B.I.1) introducing aniline (1) into the reactor of step B.I) at an aniline mass flow rate m1 commencing at the point in time t0; B.I.2) introducing of acid (3) before, simultaneously with or after introduction of aniline (1); B.II.1) introducing of formaldehyde (2) into the reactor of step B.II), optionally together with further aniline (1), optionally together with further acid (3), commencing at a point in time ti, proceeding from a mass flow rate m2=0 at the point in time t1 to a mass flow rate m2=m2,intended at the point in time t2, where t2>
t1>
t0;where the introduction of aniline (1) in step B.I.1) and optionally in step all) and the introduction of formaldehyde (2) in step B.II.1) occur in such a way that the instantaneous molar ratio of the total aniline (1) introduced into the reactor of step B.I) and, if present, the total aniline (1) introduced into the reactor of step B.II) to the total formaldehyde (2) introduced into the reactor of step B.II), A/Finst, is always ≧
2 and ≧
1.05 A/Ftarget during the period of time from t1 to t2. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Current AssigneeCovestro Intellectual Property GmbH & Co. KG (Covestro AG)
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Original AssigneeCovestro Deutschland AG
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InventorsHartjes, Volker, Knauf, Thomas, Wershofen, Stefan, Gruner, Klaus-Gerd
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Granted Patent
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Time in Patent OfficeDays
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Field of Search
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US Class Current
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CPC Class CodesC07C 209/78 from carbonyl compounds, e....C07C 211/50 with at least two amino gro...
