CN117510342A - Process for the preparation of diamines and polyamines of the diphenylmethane series with improved 2,4-MDA selectivity - Google Patents
Process for the preparation of diamines and polyamines of the diphenylmethane series with improved 2,4-MDA selectivity Download PDFInfo
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- 229920000768 polyamine Polymers 0.000 title claims abstract description 27
- 238000002360 preparation method Methods 0.000 title claims abstract description 27
- CZZYITDELCSZES-UHFFFAOYSA-N diphenylmethane Chemical class C=1C=CC=CC=1CC1=CC=CC=C1 CZZYITDELCSZES-UHFFFAOYSA-N 0.000 title claims abstract description 24
- 150000004985 diamines Chemical class 0.000 title claims abstract description 21
- 238000000034 method Methods 0.000 title claims description 24
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 claims abstract description 132
- 238000006243 chemical reaction Methods 0.000 claims abstract description 121
- 239000003377 acid catalyst Substances 0.000 claims abstract description 72
- PAYRUJLWNCNPSJ-UHFFFAOYSA-N Aniline Chemical compound NC1=CC=CC=C1 PAYRUJLWNCNPSJ-UHFFFAOYSA-N 0.000 claims abstract description 68
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 69
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 28
- 239000012074 organic phase Substances 0.000 claims description 20
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 20
- 239000000243 solution Substances 0.000 claims description 18
- 239000000047 product Substances 0.000 claims description 17
- 238000006462 rearrangement reaction Methods 0.000 claims description 17
- 238000006386 neutralization reaction Methods 0.000 claims description 16
- 230000017105 transposition Effects 0.000 claims description 14
- 239000003513 alkali Substances 0.000 claims description 9
- 238000005406 washing Methods 0.000 claims description 8
- 239000000463 material Substances 0.000 claims description 7
- 150000007522 mineralic acids Chemical class 0.000 claims description 7
- 239000011973 solid acid Substances 0.000 claims description 7
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 claims description 6
- 150000007524 organic acids Chemical group 0.000 claims description 6
- 230000035484 reaction time Effects 0.000 claims description 6
- 150000003839 salts Chemical class 0.000 claims description 6
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims description 5
- 239000007795 chemical reaction product Substances 0.000 claims description 4
- 238000007670 refining Methods 0.000 claims description 4
- 230000003197 catalytic effect Effects 0.000 claims description 3
- 239000008098 formaldehyde solution Substances 0.000 claims description 3
- 239000007788 liquid Substances 0.000 claims description 3
- 238000005191 phase separation Methods 0.000 claims description 3
- 238000005507 spraying Methods 0.000 claims description 3
- 150000008044 alkali metal hydroxides Chemical class 0.000 claims description 2
- 229910001860 alkaline earth metal hydroxide Inorganic materials 0.000 claims description 2
- 239000008346 aqueous phase Substances 0.000 claims description 2
- 239000003456 ion exchange resin Substances 0.000 claims description 2
- 229920003303 ion-exchange polymer Polymers 0.000 claims description 2
- 239000002808 molecular sieve Substances 0.000 claims description 2
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 claims description 2
- 239000012670 alkaline solution Substances 0.000 claims 1
- 239000002734 clay mineral Substances 0.000 claims 1
- 239000000203 mixture Substances 0.000 description 16
- 239000007864 aqueous solution Substances 0.000 description 10
- 239000012071 phase Substances 0.000 description 10
- 238000004128 high performance liquid chromatography Methods 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 8
- 239000012267 brine Substances 0.000 description 6
- 238000002347 injection Methods 0.000 description 6
- 239000007924 injection Substances 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 6
- 239000003054 catalyst Substances 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 5
- 238000003756 stirring Methods 0.000 description 5
- 239000002253 acid Substances 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 4
- ZZTCPWRAHWXWCH-UHFFFAOYSA-N diphenylmethanediamine Chemical compound C=1C=CC=CC=1C(N)(N)C1=CC=CC=C1 ZZTCPWRAHWXWCH-UHFFFAOYSA-N 0.000 description 4
- ZOBQXWFQMOJTJF-UHFFFAOYSA-N 2-n-benzylbenzene-1,2-diamine Chemical compound NC1=CC=CC=C1NCC1=CC=CC=C1 ZOBQXWFQMOJTJF-UHFFFAOYSA-N 0.000 description 3
- 229920001228 polyisocyanate Polymers 0.000 description 3
- 239000005056 polyisocyanate Substances 0.000 description 3
- 230000008707 rearrangement Effects 0.000 description 3
- YBRVSVVVWCFQMG-UHFFFAOYSA-N 4,4'-diaminodiphenylmethane Chemical compound C1=CC(N)=CC=C1CC1=CC=C(N)C=C1 YBRVSVVVWCFQMG-UHFFFAOYSA-N 0.000 description 2
- HLFCOTXLSHLIBK-UHFFFAOYSA-N 4-n-benzylbenzene-1,4-diamine Chemical class C1=CC(N)=CC=C1NCC1=CC=CC=C1 HLFCOTXLSHLIBK-UHFFFAOYSA-N 0.000 description 2
- AFVFQIVMOAPDHO-UHFFFAOYSA-N Methanesulfonic acid Chemical compound CS(O)(=O)=O AFVFQIVMOAPDHO-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 229910021536 Zeolite Inorganic materials 0.000 description 2
- 239000002250 absorbent Substances 0.000 description 2
- 230000002745 absorbent Effects 0.000 description 2
- 150000001412 amines Chemical class 0.000 description 2
- 125000005442 diisocyanate group Chemical group 0.000 description 2
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 2
- 238000004821 distillation Methods 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 239000010457 zeolite Substances 0.000 description 2
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- MMCPOSDMTGQNKG-UJZMCJRSSA-N aniline;hydrochloride Chemical compound Cl.N[14C]1=[14CH][14CH]=[14CH][14CH]=[14CH]1 MMCPOSDMTGQNKG-UJZMCJRSSA-N 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- SRSXLGNVWSONIS-UHFFFAOYSA-N benzenesulfonic acid Chemical compound OS(=O)(=O)C1=CC=CC=C1 SRSXLGNVWSONIS-UHFFFAOYSA-N 0.000 description 1
- 229940092714 benzenesulfonic acid Drugs 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- CCIVGXIOQKPBKL-UHFFFAOYSA-M ethanesulfonate Chemical compound CCS([O-])(=O)=O CCIVGXIOQKPBKL-UHFFFAOYSA-M 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 229940098779 methanesulfonic acid Drugs 0.000 description 1
- OHQOKJPHNPUMLN-UHFFFAOYSA-N n,n'-diphenylmethanediamine Chemical class C=1C=CC=CC=1NCNC1=CC=CC=C1 OHQOKJPHNPUMLN-UHFFFAOYSA-N 0.000 description 1
- 230000003472 neutralizing effect Effects 0.000 description 1
- -1 polymethylene Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 159000000000 sodium salts Chemical class 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J4/00—Feed or outlet devices; Feed or outlet control devices
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
- C07C209/68—Preparation of compounds containing amino groups bound to a carbon skeleton from amines, by reactions not involving amino groups, e.g. reduction of unsaturated amines, aromatisation, or substitution of the carbon skeleton
- C07C209/78—Preparation of compounds containing amino groups bound to a carbon skeleton from amines, by reactions not involving amino groups, e.g. reduction of unsaturated amines, aromatisation, or substitution of the carbon skeleton from carbonyl compounds, e.g. from formaldehyde, and amines having amino groups bound to carbon atoms of six-membered aromatic rings, with formation of methylene-diarylamines
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
- C07C209/82—Purification; Separation; Stabilisation; Use of additives
- C07C209/84—Purification
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
- C07C209/82—Purification; Separation; Stabilisation; Use of additives
- C07C209/86—Separation
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention relates to the technical field of preparation of diamines and polyamines of diphenylmethane series, and provides a preparation method of diamines and polyamines of diphenylmethane series, which improves the selectivity of 2, 4-MDA. In the preparation method, formaldehyde and aniline are subjected to contact reaction in the presence of an acid catalyst to prepare diamines and polyamines of the diphenylmethane series, and the acid catalyst is added to a reaction system in multiple steps based on the total amount of the acid catalyst.
Description
Technical Field
The invention relates to the technical field of preparation of diamines and polyamines of diphenylmethane series, in particular to a preparation method of diamines and polyamines of diphenylmethane series, which improves the selectivity of 2,4-MDA
Background
The di-and polyamines (DAM) of the diphenylmethane series are understood to mean the following types of amines and mixtures of amines:
here, n represents a natural number of 0 or more, and n=0 is referred to as diaminodiphenylmethane, abbreviated as diamine; n is n>At 0, the polyamine-based polyphenylmethanes, simply referred to as polyamines, and mixtures of these two types are referred to as diamines and polyamines of the diphenylmethane series. Wherein NH in DAM 2 The products derived from the substitution of the groups entirely by NCO groups are diisocyanates of the diaminodiphenylmethane series, polyisocyanates of the diaminodiphenylmethane series or polyisocyanate of the diiminopolyphenylene polymethylene series or diisocyanates and polyisocyanates of the diaminodiphenylmethane series (hereinafter referred to as MDI) which are used for the production of polyurethanes.
Methods for the preparation of DAM are generally well known in the art and are described in A number of published patents and publications, such as U.S. Pat. No. 2009/024777, EP-A-451442 and WO-A-99/40059, where DAM is prepared by A continuous, semi-continuous or discontinuous reaction process, typically using aniline to react with hydrochloric acid to form aniline hydrochloride, followed by addition of formaldehyde to the reactor to form DAM hydrochloride, followed by neutralization, water washing and separation of the organic and inorganic phases to give crude DAM, purification to give DAM, and phosgenation to give monomeric or polymeric MDI.
In conventional large-scale industrial production processes, all aimed at the production of highly selective 4, 4-methylenedianiline (4, 4-MDA), as in JP 2012 131720a, relates to a process for producing methylenedianiline derivatives (MDA derivatives) in the presence of a zeolite catalyst in high yield and high selectivity to 4,4 MDA; JP 2013 095724a relates to a process for preparing aromatic polyamines in high yield in the presence of a zeolite catalyst, wherein 4,4 MDA can be obtained with high selectivity; CN 114829000a provides a method for heterogeneous synthesis of methylenedianiline involving a catalytic material that can achieve high 4,4-MDA isomer molar ratios.
Since 2,4-MDA is the main component in the preparation of MDI-50, the isomer ratio in DAM directly affects the MDI-50 production. However, in the prior art, the technical solutions disclosed in the above documents cannot effectively prepare DAM with high selectivity of 2,4-MDA, and further cannot regulate the content of 2,4-MDA isomer according to the requirement of downstream products.
Disclosure of Invention
The invention provides a preparation method of di-amine and polyamine of diphenyl methane series, which improves the selectivity of 2,4-MDA, and the preparation method can improve the selectivity of 2, 4-MDA.
The invention provides the following technical scheme for achieving the purpose:
the present invention provides a process for producing diamines and polyamines of the diphenylmethane series, which improves the selectivity of 2,4-MDA, formaldehyde and aniline being reacted in contact in the presence of an acid catalyst to produce the diamines and polyamines of the diphenylmethane series, and the acid catalyst being added to the reaction system in multiple steps based on the total amount of the acid catalyst.
The invention improves the process for preparing the diamine and polyamine of the diphenylmethane series by taking formaldehyde, aniline and acid catalyst as reaction basic raw materials, and the inventor discovers that in the process of preparing the diamine and polyamine (DAM) of the diphenylmethane series by reacting formaldehyde and aniline in the presence of the acid catalyst, the acid catalyst is added into a reaction system for multiple times in a multi-step adding mode, and compared with the process of adding all the acid catalyst into the reaction system in one step, the selectivity of 2,4-MDA can be obviously improved.
In a preferred embodiment, the acid catalyst is divided into a first part of acid catalyst and a second part of acid catalyst based on the total amount of the acid catalyst; the preparation method comprises the following steps:
s1) carrying out a first-stage reaction of formaldehyde and aniline in the presence of the first partial acid catalyst; the first part of acid catalyst is added into the reaction system in a one-step or multi-step adding mode;
s2) carrying out second-stage reaction on the reaction material obtained in the step S1) in the presence of the second part of acid catalyst; the second part of acid catalyst is added into the reaction system in a one-step or multi-step adding mode;
s3) carrying out transposition rearrangement reaction on the reaction material obtained in the step S2) to obtain a reaction product containing diamine and polyamine of diphenylmethane series;
s4) carrying out neutralization reaction on the reaction product obtained in the step S3), and then separating and refining to obtain the di-amine and polyamine products of the diphenylmethane series.
By adopting the preferable mode, formaldehyde, aniline and partial acid catalyst are subjected to the first-stage reaction in advance, then the residual acid catalyst is added to carry out the second-stage reaction, and then the transposition rearrangement reaction is carried out, so that the selectivity of 2,4-MDA is further improved. In the first-stage reaction, the first part of the acid catalyst can be added in one step or multiple steps, preferably multiple steps, so that the selectivity of the 2,4-MDA is further improved. The second part of the acid catalyst may also be added in one step or in multiple steps, preferably in multiple steps, in order to further increase the selectivity of the 2, 4-MDA. Meanwhile, the inventor discovers that by adjusting the adding mode of the first part of acid catalyst and/or the second part of acid catalyst, for example, one-step addition is adopted, or multiple steps of addition are adopted and specific adding times are adjusted, different phases can be changed to generate o-aminobenzyl aniline acid salt and p-aminobenzyl aniline salt with different proportions, further different proportions of 2,4-MDA isomers are generated in the rearrangement process, the adjustment of the selectivity of 2,4-MDA can be realized, and therefore, the specific requirements of the content of 2,4-MDA in different DAM products can be easily and flexibly met, and the product refinement control is realized.
In a preferred embodiment, in the step S1), the reaction temperature of the first stage reaction is 20 to 150 ℃, for example, 20 ℃, 40 ℃, 50 ℃, 60 ℃, 80 ℃, 100 ℃, 120 ℃, 140 ℃, 150 ℃, etc.;
in the step S2), the reaction temperature of the second stage reaction is 20 to 180 ℃, for example, 20 ℃, 40 ℃, 60 ℃, 80 ℃, 100 ℃, 120 ℃, 140 ℃, 150 ℃, 170 ℃, 180 ℃, etc., preferably 35 to 95 ℃;
in the step S3), the reaction temperature of the rearrangement reaction is 55 to 200 ℃, for example 55 ℃, 80 ℃, 100 ℃, 103 ℃, 105 ℃, 120 ℃, 140 ℃, 150 ℃, 170 ℃, 180 ℃, 200 ℃, etc.;
and the reaction temperature of the transposition rearrangement reaction is higher than that of the second-stage reaction, which is higher than that of the first-stage reaction.
The inventor discovers that the preparation method adopts the reaction temperature to carry out the steps S1) to S3), and ensures that the reaction temperature of the transposition rearrangement reaction is higher than that of the second stage, and the reaction temperature of the second stage is higher than that of the first stage, thereby being beneficial to further improving the selectivity of the 2, 4-MDA.
More preferably, in step S1), the reaction temperature of the first stage reaction is 35-95 ℃, preferably 50-95 ℃, more preferably 55-95 ℃, and the first stage reaction is performed at the preferred reaction temperature, which is beneficial to further significantly improving the selectivity of 2, 4-MDA.
More preferably, in the step S2), the reaction temperature of the second stage reaction is 35-95 ℃, which is favorable for further improving the selectivity of the 2, 4-MDA.
More preferably, in step S3), the reaction temperature of the rearrangement reaction is preferably 70-150 ℃, more preferably 105-150 ℃, and the rearrangement reaction is performed at the preferred reaction temperature, which is favorable for further significantly improving the selectivity of 2, 4-MDA.
The inventor discovers that the selectivity of the 2,4-MDA can be adjusted by adjusting the reaction temperature of the step S1), the step S2) and/or the step S3), thereby being beneficial to flexibly meeting the specific requirements of the 2,4-MDA content in different DAM products and realizing the product refinement control.
In some embodiments, the reaction time of step S1) is 1.5 to 500 minutes, for example 1.5 minutes, 5 minutes, 20 minutes, 50 minutes, 100 minutes, 150 minutes, 300 minutes, 400 minutes, 500 minutes, etc., preferably 30 to 300 minutes. In some embodiments, the reaction time of step S2) is 1.5 to 500 minutes, for example 1.5 minutes, 5 minutes, 20 minutes, 50 minutes, 100 minutes, 150 minutes, 300 minutes, 400 minutes, 500 minutes, etc., preferably 5 to 300 minutes. In some embodiments, the reaction time of step S3) is 1 to 10 hours, for example 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 7 hours, 8 hours, 10 hours, etc., preferably 2 to 5 hours.
In some embodiments, the first portion of acid catalyst comprises from 5 to 99%, such as from 5%, 8%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 99%, etc., preferably from 10 to 60%, by mass based on the total amount of acid catalyst. The preferred amount of the first portion of acid catalyst is used in a ratio that facilitates higher 2,4-MDA selectivity. In addition, the preparation method can change different stages to generate o-aminobenzyl aniline acid salt with different proportions by adjusting the adding proportion of the first partial acid catalyst, further generate 2,4-MDA isomer with different proportions in the rearrangement process, realize the adjustment of the selectivity of 2,4-MDA, and further easily and flexibly meet the specific requirements of the content of 2,4-MDA in different DAM products and realize the fine control of the products.
In some embodiments, in step S1), the aniline is pre-reacted in contact with at least a portion of the first portion of the acid catalyst before the formaldehyde is added to the reaction system, and then the formaldehyde is added to continue the reaction. In this way, the first portion of the acid catalyst may be added to the reaction system in one or more steps to contact the aniline for reaction before formaldehyde is added to the reaction system; or before adding formaldehyde, part of the first part of acid catalyst can be added into the reaction system to contact and react with aniline in one step or multiple steps, the rest of the first part of acid catalyst is added into the reaction system in the formaldehyde adding process or after adding formaldehyde, and the adding mode can also be one-step adding or multiple steps adding. Preferably, in this mode, the reaction temperature after adding the formaldehyde in step S1) is higher than the reaction temperature at which the pre-reaction is performed before adding the formaldehyde, preferably the reaction temperature after adding the formaldehyde is 30 to 150 ℃, such as 30 ℃, 40 ℃, 60 ℃, 80 ℃, 100 ℃, 120 ℃, 140 ℃, 150 ℃, etc., preferably 35 to 95 ℃, more preferably 55 to 95 ℃, more preferably 70 to 95 ℃, and the preferred reaction temperature is used to further improve the 2,4-MDA selectivity.
Further, in some preferred embodiments, in step S1), in the first stage reaction, the reaction temperature after adding formaldehyde is controlled to be 35-95 ℃, preferably 55-95 ℃, more preferably 70-95 ℃; in the step S2), the reaction temperature of the second-stage reaction is controlled to be higher than that of the first-stage reaction, and is preferably 35-95 ℃; in step S3), the reaction temperature of the transposition rearrangement reaction is controlled to be 70-150 ℃, preferably 105-150 ℃ and higher than the reaction temperature of the second-stage reaction. The use of this preferred scheme facilitates further enhanced 2,4-MDA selectivity.
In some embodiments, in step S1), the aniline is contacted with at least a portion of the first portion of the acid catalyst initially added to the reaction system in the presence of formaldehyde. That is, the acid catalyst initially added to the reaction system is in contact with aniline in the presence of formaldehyde. Wherein, in step S1), the acid catalyst initially added to the reaction system may be a part or all of the acid catalyst from the first part; in this embodiment, the first portion of the acid catalyst may be added to the reaction system in one step or in multiple steps.
In particular, the step S1), step S2) and/or step S3) may be performed in one or more reactors. For example, step S1), step S2) and/or step S3) are carried out in the same reactor or transferred to different reactors, and when a plurality of reactors are involved, the reactors may be connected in series, and the specific number of the reactors required may be reasonably selected and determined by those skilled in the art according to the actual requirements of the reaction.
In particular, the reaction processes of steps S1), S2) and S3) may be carried out in a batch-wise manner or in a continuous manner, wherein continuous feed and continuous discharge are present in the reaction process when using a continuous manner.
Further, in step S4), the neutralization reaction is performed by adding an alkali solution, which is one or more of an alkali metal hydroxide solution and an alkaline earth metal hydroxide solution, and specifically, the neutralization reaction may be performed using an alkali solution conventionally used in the art. Preferably, the lye is sodium hydroxide solution and/or potassium hydroxide solution, in particular, for example, sodium hydroxide aqueous solution, potassium hydroxide aqueous solution. The alkali liquor is preferably 20-55% by mass, more preferably 32-50% by mass. When the acid catalyst is organic acid and/or inorganic acid, the alkali liquor is prepared by using OH - Calculated as H for the acid catalyst + The molar ratio of the lye to the acid catalyst is 1.0 to 3.0, preferably 1.02 to 1.30. The neutralization reaction may be carried out in a neutralization reactor, preferably a stirred reactor.
Further, the separating and refining includes: and (3) carrying out two-phase separation on the mixed liquid obtained by the neutralization reaction to obtain a salt-containing aqueous phase and an organic phase containing diamine and polyamine of diphenylmethane series, and washing the organic phase with water and removing aniline to obtain the diamine and polyamine products of the diphenylmethane series. Wherein the two-phase separation can be carried out in a two-phase separator, preferably a static demixing device. Specifically, the brine-containing phase can be extracted and stripped to obtain waste brine, and the waste brine is sent to downstream electrolysis for alkali and chlorine production, and the treatment process can be carried out by adopting a corresponding conventional process in the field, which is not described in detail. The aniline removal treatment of the organic phase may be carried out by distillation under reduced pressure (while also removing water), and the refined DAM product may be obtained by distillation under reduced pressure.
Further, the acid catalyst is selected from one or more of organic acid, inorganic acid and solid acid, wherein the organic acidFor example, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, etc., and inorganic acids, for example, one or more of hydrochloric acid, sulfuric acid, phosphoric acid, etc. The acid catalyst is preferably hydrochloric acid, more preferably 30 to 37wt% hydrochloric acid; preferably, when the acid catalyst is an organic acid and/or an inorganic acid, H is used as the acid catalyst + The molar ratio of the total of the acid catalyst and the aniline used is 0.01 to 0.80, for example 0.01, 0.05, 0.10, 0.30, 0.40, 0.60, 0.80, etc., more preferably 0.05 to 0.40. The solid acid can be a solid acid catalyst with a catalytic effect such as a molecular sieve, an ion exchange resin, natural clay ore and the like, and the dosage of the solid acid catalyst can be specifically adjusted according to different types and types of the solid acid catalyst by a person skilled in the art, and the dosage of alkali liquor required by the subsequent neutralization reaction is adjusted.
Further, the molar ratio of the formaldehyde amount to the aniline amount is 0.20 to 0.85, for example, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.85, etc., preferably 0.30 to 0.60. Preferably, the formaldehyde is added to the reaction system in the form of a formaldehyde solution having a formaldehyde mass fraction of 15-55%, preferably 30-50%. Formaldehyde can be obtained, for example, by absorbing formaldehyde in a gas phase by an absorbent, for example, pure water, brine (brine concentration, for example, 0.1 to 26 wt%) or the like is used as the absorbent to absorb formaldehyde solution, and brine, for example, sodium salt aqueous solution or the like, specifically, aqueous solution such as sodium sulfate, sodium chloride or the like.
Further, in the preparation method of the invention, formaldehyde is added into the reaction system in a one-step or multi-step adding mode. Preferably, the formaldehyde is added to the reaction system by one or more of multi-drop addition, spraying and direct current.
The term "direct current" refers to that the inflow mode of materials does not interfere with the dripping, spraying and other modes, and the materials enter the reaction system through a natural direct inflow mode.
Herein, "multiple" in "multiple steps" or "multiple" and the like means two or more.
The technical scheme provided by the invention has the following beneficial effects:
compared with the process of adding all acid catalysts into a reaction system in one step, the preparation method provided by the invention can obviously improve the selectivity and yield of 2, 4-MDA.
According to the preparation method disclosed by the invention, the acid catalyst is added in multiple steps, so that the generation proportion of the o-aminobenzyl aniline acid salt and the p-aminobenzyl aniline acid salt can be flexibly regulated in different reaction stages, and further, 2,4-MDA isomers with different proportions are generated in the rearrangement process, the ratio requirements of MDI-50 and MDI-100 in downstream products can be flexibly met, and the product refinement control can be easily realized.
Detailed Description
In order that the invention may be readily understood, a further description of the invention will be provided with reference to the following examples. It should be understood that the following examples are only for better understanding of the present invention and are not meant to limit the present invention to the following examples.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The term "and/or" as may be used herein includes any and all combinations of one or more of the associated listed items. The terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
Where specific experimental steps or conditions are not noted in the examples, they may be performed according to the operations or conditions of the corresponding conventional experimental steps in the art. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.
Aniline: 94% by weight, wanhua chemical (Fujian) Co., ltd.
The isomers of refined DAM were analyzed by high performance liquid chromatography in examples and comparative examples.
Example 1:
the DAM was prepared as follows:
1) Aniline (200 g,94 wt%), 33wt% hydrochloric acid (13.5 g, 28.7% mass ratio in total hydrochloric acid) and reacting at constant temperature of 50 ℃ for 5min;
2) After the reaction is finished, adding formaldehyde aqueous solution (69 g, the mass concentration of formaldehyde is 37%) in a dropwise manner, and maintaining the temperature at 65 ℃ for 2 hours;
3) After the reaction, 33wt% hydrochloric acid (33.5 g, the mass ratio of the total amount of the hydrochloric acid is 71.3%) is added by adopting a direct current injection mode, the temperature is maintained at 95 ℃, and the reaction is carried out for 1 hour; then continuously heating to 103 ℃ and carrying out transposition rearrangement reaction for 1 hour;
4) After the reaction, adding aqueous sodium hydroxide solution (40 g, the concentration is 50 wt%) into the mixture, and stirring the mixture to neutralize the mixture at 90 ℃ for 30min;
5) After the neutralization reaction is finished, transferring the reaction solution to a separating funnel, separating out a water phase and an organic phase, taking an upper organic phase, washing the upper organic phase by pure water, and removing water and aniline through a rectifying tower to obtain the refined DAM.
The isomer of the purified DAM was analyzed by high performance liquid chromatography, and the results are shown in Table 1.
Example 2: (As compared with example 1, the hydrochloric acid addition ratio of step 1) and step 3) was changed
The DAM was prepared as follows:
1) Aniline (200 g,94 wt%), 33wt% hydrochloric acid (18.0 g, 38.3% mass ratio in total hydrochloric acid) and reacting at a constant temperature of 50 ℃ for 5min;
2) After the reaction is finished, adding formaldehyde aqueous solution (69 g, the mass concentration of formaldehyde is 37%) in a dropwise manner, and maintaining the temperature at 65 ℃ for 2 hours;
3) After the reaction, adding 33wt% hydrochloric acid (29 g, the mass ratio of the total amount of the hydrochloric acid is 61.7%) by adopting a direct current injection mode, and maintaining the temperature at 95 ℃ for reaction for 1 hour; then continuously heating to 103 ℃ and carrying out transposition rearrangement reaction for 1 hour;
4) After the reaction, adding aqueous sodium hydroxide solution (40 g, the concentration is 50 wt%) into the mixture, and stirring the mixture to neutralize the mixture at 90 ℃ for 30min;
5) After the neutralization reaction is finished, transferring the reaction solution to a separating funnel, separating out a water phase and an organic phase, taking an upper organic phase, washing the upper organic phase by pure water, and removing water and aniline through a rectifying tower to obtain the refined DAM.
The isomer of the purified DAM was analyzed by high performance liquid chromatography, and the results are shown in Table 1.
Example 3
Reference example 2 was made, except that: the reaction temperature of step 2) was raised to 85 ℃. Other preparation steps and conditions were identical to those of example 2.
The isomer of the purified DAM obtained in example 3 was analyzed by a high performance liquid chromatograph, and the results are shown in Table 1.
Example 4:
reference example 2 was made, except that: the reaction temperature of the step 2) is raised to 85 ℃, and the temperature of the step 3) for carrying out the transposition rearrangement reaction is raised to 120 ℃. Other preparation steps and conditions were identical to those of example 2.
The isomer of the purified DAM of example 4 was analyzed by high performance liquid chromatography, and the results are shown in Table 1.
Example 5: (compared with example 4, part of the hydrochloric acid in step 1) was added in step 2)
The DAM was prepared as follows:
1) Aniline (200 g,94 wt%), 33wt% hydrochloric acid (9.0 g, mass ratio of hydrochloric acid total amount about 19.15%) and reacting at constant temperature of 50 ℃ for 5min;
2) After the reaction, dropwise adding formaldehyde aqueous solution (69 g, 37% of formaldehyde mass concentration), and adding 33wt% hydrochloric acid (9 g, 19.15% of the total amount of hydrochloric acid mass ratio) by direct current injection, maintaining the temperature at 85 ℃, and reacting for 2 hours;
3) After the reaction, 33wt% hydrochloric acid (29 g, mass ratio of the total amount of hydrochloric acid is about 61.7%) was added by direct current injection, and the temperature was maintained at 95℃for 1 hour; then continuously heating to 120 ℃ to carry out transposition rearrangement reaction for 1 hour;
4) After the reaction, adding aqueous sodium hydroxide solution (40 g, the concentration is 50 wt%) into the mixture, and stirring the mixture to neutralize the mixture at 90 ℃ for 30min;
5) After the neutralization reaction is finished, transferring the reaction solution to a separating funnel, separating out a water phase and an organic phase, taking an upper organic phase, washing the upper organic phase by pure water, and removing water and aniline through a rectifying tower to obtain the refined DAM.
The isomer of the purified DAM was analyzed by high performance liquid chromatography, and the results are shown in Table 1.
Example 6
The DAM was prepared as follows:
1) Aniline (200 g,94 wt%), 37wt% hydrochloric acid (31.91 g, 20% mass ratio in total hydrochloric acid) and reacting at 20 ℃ for 5min;
2) After the reaction is finished, adding formaldehyde aqueous solution (76.82 g, formaldehyde mass concentration is 30%) in a dropwise manner, and maintaining the temperature at 30 ℃ for 2 hours;
3) After the reaction, adding 37wt% hydrochloric acid (127.63 g, which accounts for 80% of the total amount of hydrochloric acid) by direct current injection, maintaining the temperature at 95 ℃ and reacting for 1 hour; then continuously heating to 150 ℃ to carry out transposition rearrangement reaction for 1 hour;
4) After the reaction, adding aqueous sodium hydroxide solution (139.73 g, the concentration is 50 wt%) into the mixture, and stirring the mixture to neutralize the mixture at 90 ℃ for 30min;
5) After the neutralization reaction is finished, transferring the reaction solution to a separating funnel, separating out a water phase and an organic phase, taking an upper organic phase, washing the upper organic phase by pure water, and removing water and aniline through a rectifying tower to obtain the refined DAM.
The isomer of the purified DAM was analyzed by high performance liquid chromatography, and the results are shown in Table 1.
Example 7
The DAM was prepared as follows:
1) Aniline (200 g,94 wt%), 37wt% hydrochloric acid (2.03 g, mass ratio of hydrochloric acid to total amount of 33.7%) and reacting at 95 ℃ for 5min;
2) After the reaction is finished, adding formaldehyde aqueous solution (171.83 g, formaldehyde mass concentration is 30%) in a dropwise manner, and maintaining the temperature at 120 ℃ for 2 hours;
3) After the reaction, 37wt% hydrochloric acid (3.99 g, 66.3% of the total amount of hydrochloric acid) is added by direct current injection, the temperature is maintained at 125 ℃, and the reaction is carried out for 1 hour; then continuously heating to 150 ℃ to carry out transposition rearrangement reaction for 1 hour;
4) After the reaction, adding sodium hydroxide aqueous solution (5.27 g, concentration of 50 wt%) into the mixture, stirring and neutralizing the mixture at 90 ℃ for 30min;
5) After the neutralization reaction is finished, transferring the reaction solution to a separating funnel, separating out a water phase and an organic phase, taking an upper organic phase, washing the upper organic phase by pure water, and removing water and aniline through a rectifying tower to obtain the refined DAM.
The isomer of the purified DAM was analyzed by high performance liquid chromatography, and the results are shown in Table 1.
Comparative example 1:
reference example 1 was performed with the difference that: all hydrochloric acid (47 g total) was added in step 1), and the step of adding hydrochloric acid was omitted in step 3). The remaining preparation steps and conditions were identical to those of example 1.
The isomer of the purified DAM obtained in comparative example 1 was analyzed by high performance liquid chromatography, and the results are shown in Table 1.
Comparative example 2:
reference example 3 was made, except that: all hydrochloric acid (47 g total) was added in step 1), and the step of adding hydrochloric acid was omitted in step 3). The remaining preparation steps and conditions were identical to those of example 3.
The isomer of the refined DAM of comparative example 2 was analyzed by high performance liquid chromatography, and the results are shown in table 1.
Table 1 experimental results of examples and comparative examples
In table 1: the percentages are mass percentages of 2,2-MDA, 2,4-MDA and 4,4-MDA in DAM, respectively.
From a comparison of example 1 and comparative example 1, and example 3 and comparative example 2, it can be seen that adding the acid catalyst in multiple stages can significantly improve the 2,4-MDA selectivity during the preparation of DAM.
From examples 1 to 5, it is apparent that the method of the present invention can achieve the effect of adjusting the selectivity of 2,4-MDA by changing the addition ratio of the acid catalyst in a plurality of stages, the number of times of adding the acid catalyst, and/or the adjustment of the reaction temperature, etc., thereby flexibly adapting to different demands of products.
It will be readily appreciated that the above embodiments are merely examples given for clarity of illustration and are not meant to limit the invention thereto. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the invention.
Claims (11)
1. A process for the preparation of diamines and polyamines of the diphenylmethane series with improved selectivity for 2,4-MDA, formaldehyde and aniline being reacted in contact in the presence of an acid catalyst to prepare said diamines and polyamines of the diphenylmethane series, characterized in that the acid catalyst is added in a plurality of steps to the reaction system based on the total amount of the acid catalyst.
2. The method of preparing according to claim 1, wherein the acid catalyst is divided into a first part of acid catalyst and a second part of acid catalyst based on the total amount of the acid catalyst;
the preparation method comprises the following steps:
s1) carrying out a first-stage reaction of formaldehyde and aniline in the presence of the first partial acid catalyst; the first part of acid catalyst is added into the reaction system in a one-step or multi-step adding mode;
s2) carrying out second-stage reaction on the reaction material obtained in the step S1) in the presence of the second part of acid catalyst; the second part of acid catalyst is added into the reaction system in a one-step or multi-step adding mode;
s3) carrying out transposition rearrangement reaction on the reaction material obtained in the step S2) to obtain a reaction product containing diamine and polyamine of diphenylmethane series;
s4) carrying out neutralization reaction on the reaction product obtained in the step S3), and then separating and refining to obtain the di-amine and polyamine products of the diphenylmethane series.
3. The preparation method according to claim 2, characterized in that in step S1) the reaction temperature of the first stage reaction is 20-150 ℃, preferably 35-95 ℃, more preferably 55-95 ℃;
in the step S2), the reaction temperature of the second stage reaction is 20-180 ℃, preferably 35-95 ℃;
in the step S3), the reaction temperature of the transposition rearrangement reaction is 55-200 ℃, preferably 70-150 ℃, more preferably 105-150 ℃;
and the reaction temperature of the transposition rearrangement reaction is higher than that of the second-stage reaction, which is higher than that of the first-stage reaction.
4. A process according to claim 3, wherein the reaction time of step S1) is 1.5 to 500 minutes, preferably 30 to 300 minutes;
and/or the reaction time of the step S2) is 1.5-500 minutes; preferably 5 to 300 minutes;
and/or the reaction time of the step S3) is 1-10 hours; preferably 2 to 5 hours.
5. The preparation process according to any one of claims 2 to 4, wherein the mass ratio of the first part of the acid catalyst is 5 to 99%, preferably 10 to 60%, based on the total amount of the acid catalyst.
6. The process according to any one of claims 2 to 5, wherein in step S1), the aniline is pre-reacted in contact with at least part of the first part of the acid catalyst before the formaldehyde is added to the reaction system, and then the formaldehyde is added to continue the reaction; preferably, the reaction temperature after adding the formaldehyde in step S1) is higher than the reaction temperature at which the pre-reaction is performed before adding the formaldehyde, preferably the reaction temperature after adding the formaldehyde is 30-150 ℃, further preferably 35-95 ℃, still more preferably 70-95 ℃;
alternatively, in step S1), the aniline is reacted in contact with at least part of the first part of the acid catalyst initially added to the reaction system in the presence of formaldehyde.
7. The process according to any one of claims 2 to 6, wherein step S1), step S2) and/or step S3) are carried out in one or more reactors;
and/or, the reaction process of the step S1), the step S2) and the step S3) is performed in a batch mode or a continuous mode.
8. The method according to any one of claims 2 to 7, wherein in step S4) the neutralization is performed by adding an alkaline solution, which is one or more of an alkali metal hydroxide solution, an alkaline earth metal hydroxide solution, preferably a sodium hydroxide solution and/or a potassium hydroxide solution; the mass concentration of the alkali liquor is preferably 20-55%, more preferably 32-50%; when the acid catalyst is organic acid and/or inorganic acid, the alkali liquor is calculated by OH-and the acid catalyst is calculated by H + The molar ratio of the alkali liquor to the acid catalyst is 1.0 to 3.0, preferably 1.02 to 1.30;
and/or, the separating and refining comprises: and (3) carrying out two-phase separation on the mixed liquid obtained by the neutralization reaction to obtain a salt-containing aqueous phase and an organic phase containing diamine and polyamine of diphenylmethane series, and washing the organic phase with water and removing aniline to obtain the diamine and polyamine products of the diphenylmethane series.
9. The process according to any one of claims 1 to 8, wherein the acid catalyst is selected from one or more of organic acid, inorganic acid, solid acid, preferably hydrochloric acid, more preferably 30 to 37wt% hydrochloric acid;
preferably, when the acid catalyst is an organic acid and/or an inorganic acid, H is used as the acid catalyst + The molar ratio of all of the acid catalyst and the aniline used is 0.01 to 0.80, more preferably 0.05 to 0.40;
preferably, the solid acid is selected from one or more of molecular sieves, ion exchange resins, natural clay minerals with catalytic action.
10. The process according to any one of claims 1 to 9, characterized in that the molar ratio of the formaldehyde amount to the aniline amount is 0.20 to 0.85, preferably 0.30 to 0.60; preferably, the formaldehyde is added to the reaction system in the form of a formaldehyde solution having a formaldehyde mass fraction of 15-55%, preferably 30-50%.
11. The preparation method according to any one of claims 1 to 10, wherein the formaldehyde is added to the reaction system in one or more steps;
preferably, the formaldehyde is added to the reaction system by one or more of multi-drop addition, spraying and direct current.
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