CN118164859A - Preparation method of di-amine and polyamine of diphenyl methane series - Google Patents
Preparation method of di-amine and polyamine of diphenyl methane series Download PDFInfo
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- CN118164859A CN118164859A CN202410578990.0A CN202410578990A CN118164859A CN 118164859 A CN118164859 A CN 118164859A CN 202410578990 A CN202410578990 A CN 202410578990A CN 118164859 A CN118164859 A CN 118164859A
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- 229920000768 polyamine Polymers 0.000 title claims abstract description 73
- CZZYITDELCSZES-UHFFFAOYSA-N diphenylmethane Chemical class C=1C=CC=CC=1CC1=CC=CC=C1 CZZYITDELCSZES-UHFFFAOYSA-N 0.000 title claims abstract description 69
- 238000002360 preparation method Methods 0.000 title claims abstract description 33
- 238000006243 chemical reaction Methods 0.000 claims abstract description 184
- PAYRUJLWNCNPSJ-UHFFFAOYSA-N Aniline Chemical compound NC1=CC=CC=C1 PAYRUJLWNCNPSJ-UHFFFAOYSA-N 0.000 claims abstract description 145
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 claims abstract description 124
- 150000004985 diamines Chemical class 0.000 claims abstract description 60
- 239000000126 substance Substances 0.000 claims abstract description 37
- 238000000034 method Methods 0.000 claims abstract description 28
- 239000003377 acid catalyst Substances 0.000 claims abstract description 23
- 238000012546 transfer Methods 0.000 claims abstract description 23
- 230000008859 change Effects 0.000 claims abstract description 20
- 230000035484 reaction time Effects 0.000 claims abstract description 18
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 48
- 239000000047 product Substances 0.000 claims description 41
- 239000007795 chemical reaction product Substances 0.000 claims description 36
- 239000012074 organic phase Substances 0.000 claims description 33
- 239000012071 phase Substances 0.000 claims description 32
- 239000007788 liquid Substances 0.000 claims description 22
- 238000006386 neutralization reaction Methods 0.000 claims description 18
- 239000000463 material Substances 0.000 claims description 16
- 230000008569 process Effects 0.000 claims description 16
- 238000006462 rearrangement reaction Methods 0.000 claims description 16
- 150000003839 salts Chemical class 0.000 claims description 16
- 239000000654 additive Substances 0.000 claims description 15
- 238000010438 heat treatment Methods 0.000 claims description 15
- 230000017105 transposition Effects 0.000 claims description 15
- 238000005406 washing Methods 0.000 claims description 13
- 238000005191 phase separation Methods 0.000 claims description 12
- 238000007670 refining Methods 0.000 claims description 11
- 230000000996 additive effect Effects 0.000 claims description 10
- 239000003513 alkali Substances 0.000 claims description 8
- 239000011973 solid acid Substances 0.000 claims description 8
- 230000008707 rearrangement Effects 0.000 claims description 5
- 230000008016 vaporization Effects 0.000 claims description 5
- 239000008098 formaldehyde solution Substances 0.000 claims description 4
- 230000009467 reduction Effects 0.000 claims description 4
- 150000007522 mineralic acids Chemical class 0.000 claims description 3
- 150000007524 organic acids Chemical class 0.000 claims description 3
- 238000000926 separation method 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
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 65
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 63
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical group OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 33
- 239000007864 aqueous solution Substances 0.000 description 23
- 239000000243 solution Substances 0.000 description 18
- 239000003054 catalyst Substances 0.000 description 16
- 230000001276 controlling effect Effects 0.000 description 14
- 238000001704 evaporation Methods 0.000 description 14
- 230000008020 evaporation Effects 0.000 description 10
- 239000000203 mixture Substances 0.000 description 10
- 230000001105 regulatory effect Effects 0.000 description 10
- 230000003472 neutralizing effect Effects 0.000 description 9
- 238000003756 stirring Methods 0.000 description 9
- MGJURKDLIJVDEO-UHFFFAOYSA-N formaldehyde;hydrate Chemical compound O.O=C MGJURKDLIJVDEO-UHFFFAOYSA-N 0.000 description 7
- 239000012295 chemical reaction liquid Substances 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- 239000012267 brine Substances 0.000 description 5
- ZZTCPWRAHWXWCH-UHFFFAOYSA-N diphenylmethanediamine Chemical compound C=1C=CC=CC=1C(N)(N)C1=CC=CC=C1 ZZTCPWRAHWXWCH-UHFFFAOYSA-N 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 5
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- 239000002253 acid Substances 0.000 description 4
- 230000003197 catalytic effect Effects 0.000 description 4
- 238000004821 distillation Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- ZOBQXWFQMOJTJF-UHFFFAOYSA-N 2-n-benzylbenzene-1,2-diamine Chemical class NC1=CC=CC=C1NCC1=CC=CC=C1 ZOBQXWFQMOJTJF-UHFFFAOYSA-N 0.000 description 3
- 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 3
- 230000002411 adverse Effects 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 239000012948 isocyanate Substances 0.000 description 3
- 150000002513 isocyanates Chemical class 0.000 description 3
- 238000005649 metathesis reaction Methods 0.000 description 3
- 229920001228 polyisocyanate Polymers 0.000 description 3
- 239000005056 polyisocyanate Substances 0.000 description 3
- 238000003860 storage Methods 0.000 description 3
- 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
- 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
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 description 2
- -1 polymethylene Polymers 0.000 description 2
- 230000002035 prolonged effect Effects 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 239000010457 zeolite Substances 0.000 description 2
- YBRVSVVVWCFQMG-UHFFFAOYSA-N 4,4'-diaminodiphenylmethane Chemical compound C1=CC(N)=CC=C1CC1=CC=C(N)C=C1 YBRVSVVVWCFQMG-UHFFFAOYSA-N 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 229920000265 Polyparaphenylene Polymers 0.000 description 1
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 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
- 239000012670 alkaline solution Substances 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 150000001412 amines Chemical class 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
- 125000002490 anilino group Chemical group [H]N(*)C1=C([H])C([H])=C([H])C([H])=C1[H] 0.000 description 1
- 239000008346 aqueous phase Substances 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
- 239000002734 clay mineral Substances 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
- 238000004128 high performance liquid chromatography Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 239000003456 ion exchange resin Substances 0.000 description 1
- 229920003303 ion-exchange polymer Polymers 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical class C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 229940098779 methanesulfonic acid Drugs 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000002808 molecular sieve Substances 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
- 229920006389 polyphenyl polymer 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
- 238000004064 recycling Methods 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 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
- 239000007921 spray Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 238000006276 transfer reaction Methods 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
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- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention belongs to the technical field of preparation of diamines and polyamines of diphenylmethane series, and particularly relates to a preparation method of diamines and polyamines of diphenylmethane series, which comprises the steps of contacting formaldehyde and aniline in the presence of an acid catalyst and reacting to prepare the diamines and polyamines of diphenylmethane series, wherein the reaction temperature and the selective reaction time in the reaction are controlled by adopting a mode of phase change heat transfer and temperature control of low-bubble point and low-viscosity substances in a system, so as to prepare the diamines and polyamines of diphenylmethane series with controllable 4,4-MDA selectivity. The method can flexibly regulate and control the selectivity and the content of the 4,4-MDA isomer while ensuring the long-period stable operation of the device, and meets different market demands.
Description
Technical Field
The invention belongs to the technical field of preparation of diamines and polyamines of diphenylmethane series, and particularly relates to a preparation method of diamines and polyamines of diphenylmethane series with controllable 4,4-MDA selectivity.
Background
The di-and polyamines (DAM) of the diphenylmethane series are understood to be amines of the type shown in the general formula:
In the general formula, n represents a natural number which is more than or equal to 0, and a compound corresponding to n=0 is called diaminodiphenyl methane, and diamine for short; the corresponding compounds when n >0 are called polyamine-based polyphenyl methanes, simply called polyamines; mixtures of these two types of compounds are known as diamines and polyamines of the diaminodiphenylmethane series. The derived products of DAM in which all NH 2 groups are substituted with NCO groups are diisocyanates of the diaminodiphenylmethane series, polyisocyanates of the diaminodiphenylmethane series or polyimido-polyphenylene polymethylene polyisocyanates or diisocyanates and polyisocyanates of the diaminodiphenylmethane series (hereinafter referred to as MDI) can be 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 patent documents and publications, such as U.S. Pat. No. 2009/024777, EP-A-451442 and WO-A-99/40059, and DAM is prepared by A continuous, semi-continuous or discontinuous reaction process, typically using aniline to react with hydrochloric acid to form aniline hydrochloride, then adding formaldehyde to the reactor to form DAM hydrochloride, then carrying out A metathesis rearrangement reaction, neutralization, water washing process and separating the organic phase from the inorganic phase to obtain A crude DAM, which is purified to give the DAM, and then phosgenated to form monomeric or polymeric MDI.
In the traditional large-scale industrial production process, DAM with different 4,4-MDA contents is prepared by simply adjusting some parameters, such as raw material proportions of acid catalyst, formaldehyde and aniline.
Further, in order to increase the selectivity of 4,4-MDA to a greater extent, researchers have increased the selectivity of 4,4-MDA by preparing a novel solid acid catalyst. As patent document JP 2012-131720A relates to a process for preparing methylenedianiline derivatives (MDA derivatives) in the presence of a zeolite catalyst in high yield and high selectivity to 4,4-MDA; the patent document 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; patent document CN 114829000a provides a method for heterogeneous synthesis of methylenedianiline, which relates to a catalytic material that can achieve high molar ratios of 4,4-MDA isomers. However, in the process of improving the selectivity of 4,4-MDA by using a solid acid catalyst, the solid acid catalyst has the problems of short service period, easy blockage, reduced catalytic efficiency and the like, and is not beneficial to stable operation for a long period.
4,4-MDA is the main component in the preparation of MDI-100, and the isomer ratio in DAM directly affects the yield of MDI-100. However, in the prior art, the technical solutions disclosed in the above documents cannot effectively prepare the DAM product with higher 4,4-MDA selectivity, and cannot effectively produce the DAM product with high 4,4-MDA isomer content according to the downstream product requirement, so that the long-period operation of the device is realized.
In the prior art, the system temperature is regulated and controlled and the selectivity of 4,4-MDA isomer is improved in the process of externally circulating and heat-transferring the reaction liquid containing the di-and polyamine of the diphenylmethane series, which inevitably has adverse effects on the long-period stable operation of the device; particularly, when the temperature of the system is controlled to be lower than 80 ℃, the externally circulated reaction liquid can block the heat exchanger, so that the temperature of the system cannot be effectively controlled, and the method is not only an industry pain point, but also a difficult problem. Therefore, how to flexibly control the content of the 4,4-MDA isomer and effectively produce DAM products with high content of the 4,4-MDA isomer while realizing long-period operation of the device is a direction worthy of continuous research.
Disclosure of Invention
Aiming at the problem that the prior art cannot achieve both long-period operation of a production device and flexible regulation and control of system temperature and 4,4-MDA isomer selectivity, the invention aims to provide a preparation method of diamines and polyamines of diphenylmethane series with controllable 4,4-MDA selectivity.
In order to achieve the above object, the present invention provides the following technical solutions:
The preparation method of 4,4-MDA selective controllable di-and polyamine of diphenylmethane series comprises the steps of contacting formaldehyde and aniline in the presence of an acid catalyst, reacting, then carrying out transposition rearrangement, and controlling the reaction temperature in different reaction stages by adopting a phase change of low-bubble point and low-viscosity substances to carry out heat transfer and temperature control, thereby preparing 4,4-MDA selective controllable di-and polyamine of diphenylmethane series;
The low-bubble point and low-viscosity substance is the existing low-bubble point and low-viscosity substance in the system or is an additive with additional low-bubble point and low viscosity.
In some embodiments, the low bubble point, low viscosity material already present in the system is selected from aniline and/or water; the additional low bubble point, low viscosity additive is selected from methanol and/or ethanol.
Herein, the low bubble point, the bubble point range of the low viscosity substance may be, for example, 0 to 150 ℃ (e.g., 1 ℃,2 ℃,5 ℃,8 ℃, 10 ℃, 15 ℃, 20 ℃, 25 ℃,30 ℃, 50 ℃,80 ℃, 100 ℃, 125 ℃, 140 ℃), preferably 0 to 120 ℃; the viscosity may be, for example, 0 to 10 mpa.s (e.g., 0.5 mpa.s, 1 mpa.s, 2 mpa.s, 4 mpa.s, 5.5 mpa.s, 6 mpa.s, 8 mpa.s, 9 mpa.s), and preferably 0 to 5 mpa.s.
In the preparation method provided by the invention, the temperature is controlled by utilizing the phase change of the existing low-bubble point and low-viscosity substances in the system, and then the low-bubble point and low-viscosity substances in the gas phase can be condensed and returned to the reaction system through the gas phase condenser; or the temperature is controlled by heat transfer through the phase change of the externally added low-bubble point and low-viscosity additive, and then the low-bubble point and low-viscosity additive in the gas phase can be condensed and recycled into a storage tank and returned into the system as required; by the mode, continuous circulation heat removal and temperature control are further achieved, and long-period stable operation of the equipment is not affected.
In the invention, when the existing low bubble point, low viscosity substance or added low bubble point and low viscosity additive in the system are utilized to carry out phase change heat transfer and temperature control, the existing low bubble point, low viscosity substance or the added low bubble point and low viscosity additive can be vaporized under the conditions of vacuum, normal pressure, pressure or the like according to different reaction temperatures in each reaction stage, so that the bubble points of different low bubble points and low viscosity substances can be controlled in a mode of vaporizing the original system, so that the heat of the reaction system is removed by vaporization.
According to the preparation method provided by the invention, in some embodiments, the preparation method comprises the following steps:
s1) carrying out a first-stage reaction of formaldehyde and aniline in the presence of an acid catalyst; in the first-stage reaction, the temperature of the reaction system is controlled by utilizing the phase change of low-bubble point and low-viscosity substances in the system to carry out heat transfer and temperature control; the low-bubble point and low-viscosity substance is the existing low-bubble point and low-viscosity substance in the system or an additive with additional low-bubble point and low viscosity;
Preferably, the temperature control mode of the first stage reaction is to vaporize and control the temperature of the existing low-bubble point and low-viscosity substances (such as aniline and/or water) in the system; for example, the reaction temperature of the first-stage reaction can be controlled to be 10-120 ℃ and the reaction time can be controlled to be 1.5-500 minutes;
S2) carrying out second-stage reaction on the reaction product obtained in the step S1); in the second-stage reaction, the temperature control mode of the reaction system is a mode of heat transfer and temperature reduction by utilizing the phase change of low-bubble point and low-viscosity substances in the system or a mode of heating by utilizing steam; the low-bubble point and low-viscosity substance is the existing low-bubble point and low-viscosity substance in the system or an additive with additional low-bubble point and low viscosity; for example, the reaction temperature of the second stage reaction can be controlled to be 10-150 ℃ and the reaction time can be controlled to be 1.5-800 minutes in the mode;
Preferably, the reaction temperature of the second stage reaction is the same as or different from the reaction temperature of the first stage reaction;
S3) carrying out transposition rearrangement reaction on the reaction product 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.
In some embodiments, in the first stage reaction of step S1), the phase change temperature is controlled by using low bubble point, low viscosity substances (e.g., aniline and/or water) or externally added low bubble point, low viscosity additives already present in the system; for example, the existing low bubble point, low viscosity materials of the original system or the additional low bubble point, low viscosity additives can be vaporized under the conditions of vacuum or/and normal pressure or/and pressurization to adjust the reaction temperature of the system; the reaction temperature of the first stage reaction can be controlled to be 10-120 ℃ (e.g., 12 ℃, 20 ℃,25 ℃,30 ℃,50 ℃, 60 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃), preferably 15-95 ℃;
The reaction time of the first stage reaction in step S1) is 1.5 to 500 minutes (for example, 2 minutes, 5 minutes, 15 minutes, 30 minutes, 60 minutes, 100 minutes, 150 minutes, 200 minutes, 250 minutes), preferably 10 to 300 minutes.
In some embodiments, in step S1), prior to adding formaldehyde to the reaction system, aniline is contacted with an acid catalyst to perform a pre-reaction, and then formaldehyde is added to continue the reaction;
in some embodiments, in step S1), the reaction temperature after adding formaldehyde to the system is higher than the reaction temperature at which the pre-reaction is performed prior to adding formaldehyde;
in some embodiments, in step S1), the reaction temperature after adding formaldehyde is 10 to 120 ℃ (e.g., 12 ℃, 20 ℃, 25 ℃, 30 ℃, 50 ℃, 60 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃), preferably 15 to 95 ℃.
Or in some embodiments, in step S1), the aniline is contacted with an acid catalyst initially added to the reaction system in the presence of formaldehyde.
According to the preparation method provided by the invention, in the step S2), the temperature control mode can be to utilize low bubble point and low viscosity substances in the system to evaporate and cool or to heat the system by adopting steam; wherein, the low-bubble point and low-viscosity substances can be substances existing in original systems (such as aniline and/or water), or externally added low-bubble point and low-viscosity additives (such as methanol, ethanol and the like); for example, the control of the reaction temperature may be achieved by vaporizing the low bubble point, low viscosity materials already present in the original system or by vaporizing an additional low bubble point, low viscosity additive under vacuum or/and atmospheric or/and pressure.
In some embodiments, in the second stage reaction of step S2), the temperature is controlled by using the existing low-bubble point, low-viscosity substances or the externally added low-bubble point, low-viscosity additives in the system, or by using steam heating to raise the temperature; controlling the reaction temperature of the second stage reaction to 10-150 ℃ (e.g., 12 ℃,20 ℃, 25 ℃,30 ℃, 50 ℃, 60 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃, 140 ℃), preferably 15-95 ℃;
The reaction time of the second stage reaction in step S2) is 1.5 to 800 minutes (for example, 2 minutes, 5 minutes, 15 minutes, 30 minutes, 60 minutes, 100 minutes, 150 minutes, 200 minutes, 250 minutes, 300 minutes, 500 minutes, 700 minutes), preferably 10 to 600 minutes.
The formaldehyde, the aniline and the acid catalyst are subjected to the first-stage reaction in advance under the state of phase change heat transfer and temperature control of low-bubble point and low-viscosity substances, then the reaction temperature of the system is regulated to perform the second-stage reaction by the mode of phase change heat transfer and temperature reduction or steam heating and temperature rise of the low-bubble point and low-viscosity substances, and then the high Wen Zhuaiwei rearrangement reaction is performed, so that the selectivity of 4,4-MDA is further improved, and the selectivity of 2,4-MDA is reduced. In the first stage reaction, the temperature control mode is preferably used for controlling the evaporation of aniline and/or water existing in the system (preferably vacuum regulation and control of low temperature), so that the stable operation of the device is not influenced while the lower temperature control can be realized, or/and the first stage reaction time is prolonged, the selectivity of 4,4-MDA is further improved, and the selectivity of 2,4-MDA is reduced. In the second-stage reaction, the temperature control mode can also adopt low-bubble point and low-viscosity substance phase change heat transfer temperature reduction or steam heating temperature control (preferably, aniline and/or water existing in the system are gasified and controlled in a temperature control mode, the stable operation of the device is not influenced while the lower temperature control can be realized), and/or the second-stage reaction time is prolonged, so that the selectivity of 4,4-MDA is further improved, and the selectivity of 2,4-MDA is reduced.
In addition, the inventor also discovers that through the cooperative regulation and control of the reaction temperature and the reaction time of the first stage and/or the second stage, for example, the first stage and/or the second stage is adopted to keep constant temperature, or the first stage and/or the second stage is adopted to change and adjust the temperature gradient and the reaction time, the o-aminobenzyl aniline salt and the p-aminobenzyl aniline salt with different proportions can be generated in different reaction stages, and further, the 4,4-MDA isomer with different proportions is generated in the rearrangement process, so that the flexible regulation of the 4,4-MDA selectivity can be realized, and the specific requirements of the 4,4-MDA content in different DAM products can be easily and flexibly met, and the product refinement control can be realized. Meanwhile, the temperature control mode adopted by the invention can avoid the problem that the heat exchanger is blocked due to the change of the temperature of the external circulation heat transfer reaction liquid along with the change of the system temperature and the change of the impurity content, and can realize the flexible adjustment of the selectivity of 4,4-MDA and the long-period operation of the device.
In some embodiments, in step S3), the process conditions of the metathesis rearrangement reaction include: the reaction temperature is 55-200deg.C (for example, 60deg.C, 80deg.C, 100deg.C, 140deg.C, 160deg.C, 180deg.C), preferably 105-150deg.C; the reaction time is 1 to 10 hours (for example, 1.5 hours, 3 hours, 4 hours, 6 hours, 8 hours), preferably 2 to 5 hours.
In some embodiments, the reaction temperature of the metathesis rearrangement reaction of step S3) is greater than the reaction temperature of the second stage reaction of step S2).
The inventor finds that the limited reaction temperature is adopted to carry out the steps S1) -S3), and the reaction temperature of the transposition reaction is enabled to be as close as possible to the reaction temperature of the second stage under the condition of ensuring the completion of the transposition reaction, thereby being beneficial to further improving the selectivity of 4, 4-MDA.
The cooperative control of the reaction temperature and the reaction time in the step S1), the step S2) and/or the step S3) is beneficial to flexibly meeting the specific requirements of the content of 4,4-MDA in different DAM products while ensuring the stable long-period operation of the device, so as to realize the fine control of the products; and also improves the selectivity of 4, 4-MDA.
In some embodiments, step S1), step S2) and step S3) are performed in the same reactor or in multiple reactors, respectively.
In some embodiments, the reaction process of step S1), step S2) and step S3) is performed in a batch or continuous manner.
The neutralization reaction in step S4) may be a conventional operation in the art. In some embodiments, in step S4), the neutralization reaction is carried out by adding an alkaline solution, which is one or more of a solution of an alkali metal hydroxide, a solution of an alkaline earth metal hydroxide, preferably selected from an aqueous sodium hydroxide solution and/or an aqueous potassium hydroxide solution. In some embodiments, the lye is present in a mass concentration of 20-55% (e.g., 25%, 30%, 35%, 40%, 45%), preferably 32-50%.
In some embodiments, the alkali lye is calculated as OH - and the acid catalyst is calculated as H +, the molar ratio of the alkali lye to the acid catalyst is 1.0 to 3.0 (e.g., 1.02, 1.03, 1.04, 1.05, 1.08, 1.1, 1.15, 1.2, 1.25, 1.35, 1.5, 1.8, 2.0, 2.5, 2.8), preferably 1.01 to 1.30.
Herein, the separation and purification process of step S4) may be a conventional operation in the art. In some embodiments, in step S4), the separation and refinement process comprises: and (3) carrying out two-phase separation on the mixed liquid obtained by the neutralization reaction to obtain a water phase containing salt and an organic phase containing diamine and polyamine of diphenylmethane series, and then 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 may be performed in a two-phase separator, preferably a static separator. Specifically, the aqueous phase containing salt 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, and the details are omitted. The water washing procedure is a conventional operation in the art. The aniline removal treatment of the organic phase may be carried out by distillation under reduced pressure (while also removing water) to give a refined DAM product. The reduced pressure distillation may be carried out, for example, by using a rotary evaporator, a distillation column or the like to separate aniline. The process conditions for the reduced pressure distillation may also be a conventional choice in the art and will not be described in detail herein.
In some embodiments, the acid catalyst is selected from one or more of an organic acid, an inorganic acid, and a solid acid. The organic acid is, for example, one or more of methanesulfonic acid, ethanesulfonic acid, and benzenesulfonic acid; the inorganic acid is, for example, one or more of hydrochloric acid, sulfuric acid, and phosphoric acid.
The solid acid can be one or more solid acid catalysts with catalytic action selected from molecular sieves with catalytic action, ion exchange resins, natural clay minerals and the like, and the addition amount can be adjusted according to different types and types of the solid acid catalysts, and the alkali liquor dosage required by the subsequent neutralization reaction can be adjusted.
In some embodiments, the acid catalyst is aqueous hydrochloric acid; preferably, the acid catalyst is 30-37 wt% (e.g., 32wt%, 34wt%, 35 wt%) hydrochloric acid aqueous solution.
In some embodiments, the molar ratio of all of the acid catalyst and the aniline used is 0.01 to 0.80 (e.g., 0.02, 0.04, 0.06, 0.1, 0.2, 0.3, 0.5, 0.6, 0.7), preferably 0.05 to 0.40, based on H + of the acid catalyst.
In some embodiments, the formaldehyde to aniline molar ratio is 0.20 to 0.85 (e.g., 0.25, 0.35, 0.40, 0.50, 0.65, 0.80), preferably 0.30 to 0.60.
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. In some embodiments, the formaldehyde is added to the reaction system in the form of a formaldehyde solution having a formaldehyde mass fraction of 15-55% (e.g., 20%, 25%, 35%, 45%), preferably 30-50%.
In some embodiments, 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, spray addition and direct current addition. The "direct current" means that the inflow mode of the material does not interfere with the dripping, spraying and other modes, and the material enters the reaction system through a natural direct inflow mode.
In the search for improvements in processes for the preparation of diamines and polyamines of the diphenylmethane series from formaldehyde, aniline and acid catalysts, the inventors have found that the use of low-bubble-point, low-viscosity substances (e.g. aniline and/or water) already present in the system or of externally applied, low-bubble-point, low-viscosity additives, with phase-change heat-transfer temperature control, can be used as an effective temperature control means for the various reaction stages, while allowing flexible control of the system temperature and avoiding adverse effects on the stable operation of the device.
Compared with the mode of carrying out external circulation heat transfer and temperature control on the diamine and polyamine reaction liquid containing diphenylmethane series, the temperature control mode adopted by the invention can avoid adverse effects on the stable operation of the device in the process of effectively reducing the temperature of a reaction system, and can flexibly control the selectivity of 4,4-MDA and ensure the stability of long-period operation of the device and the system by reasonably regulating and controlling parameters such as the reaction temperature, the reaction time and the like; in addition, the selectivity of 4,4-MDA can be improved according to the requirement.
In the prior art, the content of heavy components in a product is generally reduced by adopting some technical means (the viscosity of the product is high when the content of the heavy components is high), so that the problem of equipment blockage can be solved. The invention skillfully utilizes the phase change heat transfer temperature control mode of low-bubble point and low-viscosity substances, and can well solve the problem of stable operation of equipment without pursuing to reduce the content of heavy components in the product. The invention solves the problem of equipment blockage in the reaction stage and realizes the long-period stable operation of the device, and simultaneously can flexibly regulate and control the reaction temperature and the reaction time, and on the basis, the two are matched by selecting the proper reaction temperature and the reaction time, 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, 4-MDA isomers with different proportions can be generated in the rearrangement process, thereby meeting the market demand of MDI-100 in downstream products and being easy to realize the refined control of the products.
Detailed Description
So that the technical features and content of the present invention can be understood in detail, preferred embodiments of the present invention will be described in more detail below. While the preferred embodiments of the present invention have been described in the examples, it should be understood that the present invention may be embodied in various forms and should not be limited to the embodiments set forth herein.
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 in accordance with the operation 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. Wherein:
Formaldehyde stream: 15-55wt%, of Wanhua chemical (Fujian) isocyanate limited company industrial park;
aniline stream: 90.0-99.9 wt.% of Wanhua chemical (Fujian) isocyanate company, inc.;
hydrochloric acid stream: 30-37wt%, of Wanhua chemical (Fujian) isocyanate Limited company industrial park;
The isomers of refined DAM were analyzed by high performance liquid chromatography in examples and comparative examples.
Example 1
The preparation of diamines and polyamines (DAM) of the diphenylmethane series is carried out as follows:
S1) adding an aniline stream with the concentration of 94wt% and a hydrochloric acid stream with the concentration of 33wt% into a reactor, and reacting for 10min at the constant temperature of 95 ℃, wherein the molar ratio of catalyst hydrochloric acid (calculated as H +) to aniline (calculated as-NH 2) is 0.40; after the reaction is finished, adding a formaldehyde water solution material flow with the concentration of 37 weight percent, adopting a mode of controlling the temperature by evaporation and heat transfer of aniline and/or water existing in the system at low pressure, controlling the pressure of the system to be 75kPaA (absolute pressure), maintaining the temperature of the system at 95 ℃, and carrying out a first-stage reaction for 30min; the molar ratio of formaldehyde to aniline (calculated as-NH 2) was 0.56;
S2) after the reaction in the first stage is finished, further adopting a mode of low-pressure evaporation heat removal and temperature control of aniline and/or water existing in the system, wherein the pressure of the system is controlled to be 75kPaA (absolute pressure), the temperature of the system is maintained to be 95 ℃, and the reaction product obtained in the step S1) is subjected to the second-stage reaction at constant temperature for 10min;
S3) after the reaction is finished, heating the system to 100 ℃, and carrying out transposition rearrangement reaction on the reaction product obtained in the step S2) for 2 hours to obtain a reaction product containing diamine and polyamine of diphenylmethane series;
S4) adding a 50wt% sodium hydroxide aqueous solution into the system after the reaction is finished, wherein the reaction temperature is 95 ℃, and stirring and neutralizing the mixture for 30min, wherein the molar ratio of the sodium hydroxide aqueous solution (calculated as OH -) to hydrochloric acid (calculated as H +) is 1.05; and then carrying out two-phase separation on the product feed liquid obtained by neutralization to obtain a water phase containing salt and an organic phase containing diamine and polyamine of diphenylmethane series, refining the organic phase, and removing aniline from the organic phase after water washing by adopting a rotary evaporator under the conditions of the temperature of 97 ℃ and the absolute pressure of 80kPaA to obtain refined products of diamine and polyamine of diphenylmethane series.
The isomer of the refined DAM was analyzed by Agilent 1260 Infinity II high performance liquid chromatograph and the pressure difference between the inlet and outlet of the heat exchanger of the reaction unit was detected, and the results are shown in table 1.
Example 2
The preparation of diamines and polyamines (DAM) of the diphenylmethane series is carried out as follows:
S1) adding an aniline stream with the concentration of 94wt% and a hydrochloric acid stream with the concentration of 33wt% into a reactor, and reacting for 10min at the constant temperature of 45 ℃, wherein the molar ratio of catalyst hydrochloric acid (calculated as H +) to aniline (calculated as-NH 2) is 0.40; after the reaction is finished, adding a formaldehyde water solution material flow with the concentration of 37 weight percent, adopting a mode of controlling the temperature by evaporation and heat transfer of aniline and/or water existing in the system at low pressure, wherein the pressure of the system is controlled to be 8 kPaA (absolute pressure), the temperature of the system is maintained at 45 ℃, and carrying out the first-stage reaction for 30min; the molar ratio of formaldehyde to aniline (calculated as-NH 2) was 0.56;
S2) after the reaction in the first stage is finished, 2S steam (2S steam refers to water vapor with absolute pressure of 0.3 MPaA) is further adopted to heat outside the system, the temperature of the system is regulated to 95 ℃, and the reaction product obtained in the step S1) is subjected to a second-stage reaction at constant temperature for 10min;
S3) after the reaction is finished, heating the system to 100 ℃, and carrying out transposition rearrangement reaction on the reaction product obtained in the step S2) for 2 hours to obtain a reaction product containing diamine and polyamine of diphenylmethane series;
S4) adding a 50wt% sodium hydroxide aqueous solution into the system after the reaction is finished, wherein the reaction temperature is 95 ℃, and stirring and neutralizing the mixture for 30min, wherein the molar ratio of the sodium hydroxide aqueous solution (calculated as OH -) to hydrochloric acid (calculated as H +) is 1.05; and then carrying out two-phase separation on the product feed liquid obtained by neutralization to obtain a water phase containing salt and an organic phase containing diamine and polyamine of diphenylmethane series, refining the organic phase, and removing aniline from the organic phase after water washing by adopting a rotary evaporator under the conditions of the temperature of 97 ℃ and the absolute pressure of 80kPaA to obtain refined products of diamine and polyamine of diphenylmethane series.
The isomer of the refined DAM was analyzed by Agilent 1260 Infinity II high performance liquid chromatograph and the pressure difference between the inlet and outlet of the heat exchanger of the reaction unit was detected, and the results are shown in table 1.
Example 3
The preparation of diamines and polyamines (DAM) of the diphenylmethane series is carried out as follows:
S1) adding an aniline stream with the concentration of 94wt% and a hydrochloric acid stream with the concentration of 33wt% into a reactor, and reacting for 10min at the constant temperature of 15 ℃, wherein the molar ratio of catalyst hydrochloric acid (calculated as H +) to aniline (calculated as-NH 2) is 0.40; after the reaction is finished, adding a formaldehyde water solution material flow with the concentration of 37 weight percent, adopting a mode of controlling the temperature by evaporation and heat transfer of aniline and/or water existing in the system at low pressure, wherein the pressure of the system is controlled to be 1.5 kPaA (absolute pressure), the temperature of the system is maintained at 15 ℃, and carrying out the first-stage reaction for 30min; the molar ratio of formaldehyde to aniline (calculated as-NH 2) was 0.56;
S2) after the reaction in the first stage is finished, 2S steam (2S steam refers to water vapor with absolute pressure of 0.3 MPaA) is further adopted to heat outside the system, the temperature of the system is regulated to 95 ℃, and the reaction product obtained in the step S1) is subjected to a second-stage reaction at constant temperature for 10min;
S3) after the reaction is finished, heating the system to 100 ℃, and carrying out transposition rearrangement reaction on the reaction product obtained in the step S2) for 2 hours to obtain a reaction product containing diamine and polyamine of diphenylmethane series;
S4) adding a 50wt% sodium hydroxide aqueous solution into the system after the reaction is finished, wherein the reaction temperature is 95 ℃, and stirring and neutralizing the mixture for 30min, wherein the molar ratio of the sodium hydroxide aqueous solution (calculated as OH -) to hydrochloric acid (calculated as H +) is 1.05; and then carrying out two-phase separation on the product feed liquid obtained by neutralization to obtain a water phase containing salt and an organic phase containing diamine and polyamine of diphenylmethane series, refining the organic phase, and removing aniline from the organic phase after water washing by adopting a rotary evaporator under the conditions of the temperature of 97 ℃ and the absolute pressure of 80kPaA to obtain refined products of diamine and polyamine of diphenylmethane series.
The isomer of the refined DAM was analyzed by Agilent 1260 Infinity II high performance liquid chromatograph and the pressure difference between the inlet and outlet of the heat exchanger of the reaction unit was detected, and the results are shown in table 1.
Example 4
The preparation of diamines and polyamines (DAM) of the diphenylmethane series is carried out as follows:
S1) adding an aniline stream with the concentration of 94wt% and a hydrochloric acid stream with the concentration of 33wt% into a reactor, and reacting for 10min at the constant temperature of 15 ℃, wherein the molar ratio of catalyst hydrochloric acid (calculated as H +) to aniline (calculated as-NH 2) is 0.40; after the reaction is finished, adding a formaldehyde water solution material flow with the concentration of 37 weight percent, adopting a mode of controlling the temperature by evaporation and heat transfer of aniline and/or water existing in the system at low pressure, wherein the pressure of the system is controlled to be 1.5 kPaA (absolute pressure), the temperature of the system is maintained at 15 ℃, and carrying out the first-stage reaction for 300min; the molar ratio of formaldehyde to aniline (calculated as-NH 2) was 0.56;
S2) after the reaction in the first stage is finished, 2S steam (2S steam refers to water vapor with absolute pressure of 0.3 MPaA) is further adopted to heat and adjust the temperature of the system to 95 ℃ outside the system, and the reaction product obtained in the step S1) is subjected to a second-stage reaction at constant temperature for 10min;
S3) after the reaction is finished, heating the system to 100 ℃, and carrying out transposition rearrangement reaction on the reaction product obtained in the step S2) for 2 hours to obtain a reaction product containing diamine and polyamine of diphenylmethane series;
S4) adding a 50wt% sodium hydroxide aqueous solution into the system after the reaction is finished, wherein the reaction temperature is 95 ℃, and stirring and neutralizing the mixture for 30min, wherein the molar ratio of the sodium hydroxide aqueous solution (calculated as OH -) to hydrochloric acid (calculated as H +) is 1.05; and then carrying out two-phase separation on the product feed liquid obtained by neutralization to obtain a water phase containing salt and an organic phase containing diamine and polyamine of diphenylmethane series, refining the organic phase, and removing aniline from the organic phase after water washing by adopting a rotary evaporator under the conditions of the temperature of 97 ℃ and the absolute pressure of 80kPaA to obtain refined products of diamine and polyamine of diphenylmethane series.
The isomer of the refined DAM was analyzed by Agilent 1260 Infinity II high performance liquid chromatograph and the pressure difference between the inlet and outlet of the heat exchanger of the reaction unit was detected, and the results are shown in table 1.
Example 5
The preparation of diamines and polyamines (DAM) of the diphenylmethane series is carried out as follows:
S1) adding an aniline stream with the concentration of 94wt% and a hydrochloric acid stream with the concentration of 33wt% into a reactor, and reacting for 10min at the constant temperature of 15 ℃, wherein the molar ratio of catalyst hydrochloric acid (calculated as H +) to aniline (calculated as-NH 2) is 0.40; after the reaction is finished, adding a formaldehyde water solution material flow with the concentration of 37 weight percent, adopting a mode of controlling the temperature by evaporation and heat transfer of aniline and/or water existing in the system at low pressure, wherein the pressure of the system is controlled to be 1.5 kPaA (absolute pressure), the temperature of the system is maintained at 15 ℃, and carrying out the first-stage reaction for 300min; the molar ratio of formaldehyde to aniline (calculated as-NH 2) was 0.56;
s2) after the reaction in the first stage is finished, 2S steam (2S steam refers to water vapor with absolute pressure of 0.3 MPaA) is further adopted to heat and adjust the system temperature to 20 ℃ outside the system, and the reaction product obtained in the step S1) is subjected to a second-stage reaction at constant temperature for 300min;
s3) after the reaction is finished, heating the system to 150 ℃, and carrying out transposition rearrangement reaction on the reaction product obtained in the step S2) for 2 hours to obtain a reaction product containing diamine and polyamine of diphenylmethane series;
S4) adding a 50wt% sodium hydroxide aqueous solution into the system after the reaction is finished, wherein the reaction temperature is 95 ℃, and stirring and neutralizing the mixture for 30min, wherein the molar ratio of the sodium hydroxide aqueous solution (calculated as OH -) to hydrochloric acid (calculated as H +) is 1.05; and then carrying out two-phase separation on the product feed liquid obtained by neutralization to obtain a water phase containing salt and an organic phase containing diamine and polyamine of diphenylmethane series, refining the organic phase, and removing aniline from the organic phase after water washing by adopting a rotary evaporator under the conditions of the temperature of 97 ℃ and the absolute pressure of 80kPaA to obtain refined products of diamine and polyamine of diphenylmethane series.
The isomer of the refined DAM was analyzed by Agilent 1260 Infinity II high performance liquid chromatograph and the pressure difference between the inlet and outlet of the heat exchanger of the reaction unit was detected, and the results are shown in table 1.
Example 6
The preparation of diamines and polyamines (DAM) of the diphenylmethane series is carried out as follows:
S1) adding an aniline stream with the concentration of 94wt% and a hydrochloric acid stream with the concentration of 33wt% into a reactor, and reacting for 10min at the constant temperature of 15 ℃, wherein the molar ratio of catalyst hydrochloric acid (calculated as H +) to aniline (calculated as-NH 2) is 0.40; after the reaction is finished, adding a formaldehyde water solution material flow with the concentration of 37 weight percent, adopting a mode of controlling the temperature by evaporation and heat transfer of aniline and/or water existing in the system at low pressure, wherein the pressure of the system is controlled to be 1.5 kPaA (absolute pressure), the temperature of the system is maintained at 15 ℃, and carrying out the first-stage reaction for 300min; the molar ratio of formaldehyde to aniline (calculated as-NH 2) was 0.56;
s2) after the reaction in the first stage is finished, 2S steam (2S steam refers to water vapor with absolute pressure of 0.3 MPaA) is further adopted to heat and adjust the system temperature to 20 ℃ outside the system, and the reaction product obtained in the step S1) is subjected to a second-stage reaction at constant temperature for 300min;
S3) after the reaction is finished, heating the system to 70 ℃, and carrying out transposition rearrangement reaction on the reaction product obtained in the step S2) for 5 hours to obtain a reaction product containing diamine and polyamine of diphenylmethane series;
S4) adding a 50wt% sodium hydroxide aqueous solution into the system after the reaction is finished, wherein the reaction temperature is 95 ℃, and stirring and neutralizing the mixture for 30min, wherein the molar ratio of the sodium hydroxide aqueous solution (calculated as OH -) to hydrochloric acid (calculated as H +) is 1.05; and then carrying out two-phase separation on the product feed liquid obtained by neutralization to obtain a water phase containing salt and an organic phase containing diamine and polyamine of diphenylmethane series, refining the organic phase, and removing aniline from the organic phase after water washing by adopting a rotary evaporator under the conditions of the temperature of 97 ℃ and the absolute pressure of 80kPaA to obtain refined products of diamine and polyamine of diphenylmethane series.
The isomer of the refined DAM was analyzed by Agilent 1260 Infinity II high performance liquid chromatograph and the pressure difference between the inlet and outlet of the heat exchanger of the reaction unit was detected, and the results are shown in table 1.
Example 7
The preparation of diamines and polyamines (DAM) of the diphenylmethane series is carried out as follows:
S1) adding an aniline stream with the concentration of 94wt% and a hydrochloric acid stream with the concentration of 33wt% into a reactor, and reacting for 10min at the constant temperature of 60 ℃, wherein the molar ratio of catalyst hydrochloric acid (calculated as H +) to aniline (calculated as-NH 2) is 0.40; after the reaction is finished, adding a formaldehyde water solution material flow with the concentration of 37 weight percent, adopting a mode of controlling the temperature by evaporation and heat transfer of aniline and/or water existing in the system at low pressure, controlling the pressure of the system to be 75 kPaA (absolute pressure), maintaining the temperature of the system at 95 ℃, and carrying out a first-stage reaction for 300min; the molar ratio of formaldehyde to aniline (calculated as-NH 2) was 0.56;
S2) after the reaction in the first stage is finished, a temperature control mode of evaporating and removing heat of aniline and/or water existing in the system under low pressure is further adopted, wherein the pressure of the system is controlled to be 15 kPaA (absolute pressure), the temperature of the system is regulated to 55 ℃, and the reaction product obtained in the step S1) is subjected to a second-stage reaction at constant temperature for 300min;
s3) after the reaction is finished, heating the system to 150 ℃, and carrying out transposition rearrangement reaction on the reaction product obtained in the step S2) for 2 hours to obtain a reaction product containing diamine and polyamine of diphenylmethane series;
S4) adding a 50wt% sodium hydroxide aqueous solution into the system after the reaction is finished, wherein the reaction temperature is 95 ℃, and stirring and neutralizing the mixture for 30min, wherein the molar ratio of the sodium hydroxide aqueous solution (calculated as OH -) to hydrochloric acid (calculated as H +) is 1.05; and then carrying out two-phase separation on the product feed liquid obtained by neutralization to obtain a water phase containing salt and an organic phase containing diamine and polyamine of diphenylmethane series, refining the organic phase, and removing aniline from the organic phase after water washing by adopting a rotary evaporator under the conditions of the temperature of 97 ℃ and the absolute pressure of 80kPaA to obtain refined products of diamine and polyamine of diphenylmethane series.
The isomer of the refined DAM was analyzed by Agilent 1260 Infinity II high performance liquid chromatograph and the pressure difference between the inlet and outlet of the heat exchanger of the reaction unit was detected, and the results are shown in table 1.
Example 8
The procedure for the preparation of diamines and polyamines (DAM) from the diphenylmethane series is described in example 1, with the difference that in step S1) a temperature control method is used for removing heat from the methanol added at atmospheric pressure by evaporation, the system temperature is maintained at 95℃and the reaction is carried out for 30min; and, in the step S2), a temperature control mode of evaporating and removing heat to the externally added methanol under normal pressure is adopted, the temperature of the system is maintained at 95 ℃, and the reaction is carried out for 10min; the mass of the methanol added in the step S1) and the step S2) is 10 weight percent of the total mass of the reaction solution; the remaining steps were the same as in example 1.
The test results are shown in Table 1.
Example 9
The preparation steps of diamines and polyamines (DAM) of diphenylmethane series refer to example 2, except that in step S1), a temperature control mode of evaporating and removing heat from the added methanol at normal pressure is adopted, the temperature of the system is maintained at 90 ℃, and the first-stage reaction is carried out for 30min, wherein the mass of the added methanol is 15wt% of the total mass of the reaction solution; and, in step S2), refluxing 10wt% of the condensed liquid methanol stream to the system, maintaining the system temperature at 95 ℃ by adopting a temperature control mode for evaporating and removing heat from the methanol at normal pressure, carrying out a second-stage reaction at constant temperature for 10min on the reaction product obtained in step S1), and storing the rest 5wt% of the condensed liquid methanol stream in a storage tank; after the step S2) is finished, condensing and recycling the residual vaporized methanol in the system to a storage tank, and removing the reaction system; the remaining steps were the same as in example 2.
The test results are shown in Table 1.
Comparative example 1 (compared to example 1)
The preparation of diamines and polyamines (DAM) of the diphenylmethane series is carried out as follows:
S1) adding an aniline stream with the concentration of 94wt% and a hydrochloric acid stream with the concentration of 33wt% into a reactor, and reacting for 10min at the constant temperature of 95 ℃, wherein the molar ratio of catalyst hydrochloric acid (calculated as H +) to aniline (calculated as-NH 2) is 0.40; after the reaction is finished, adding a formaldehyde aqueous solution material flow with the concentration of 37wt%, and maintaining the system temperature at 95 ℃ by adopting a mode of external circulation heat removal and temperature control of a diamine and polyamine reaction solution containing diphenylmethane series in a heat exchanger, wherein the molar ratio of formaldehyde to aniline (calculated by-NH 2) is 0.56;
S2) after the reaction in the first stage is finished, regulating the temperature of the system to 95 ℃ in a mode of external circulation heat removal of a reaction solution containing di-amine and polyamine of the diphenyl methane series, and carrying out a second-stage reaction for 10min at a constant temperature on the reaction product obtained in the step S1);
S3) after the reaction is finished, heating the system to 100 ℃, and carrying out transposition rearrangement reaction on the reaction product obtained in the step S2) for 2 hours to obtain a reaction product containing diamine and polyamine of diphenylmethane series;
S4) adding a 50wt% sodium hydroxide aqueous solution into the system after the reaction is finished, wherein the reaction temperature is 95 ℃, and stirring and neutralizing the mixture for 30min, wherein the molar ratio of the sodium hydroxide aqueous solution (calculated as OH -) to hydrochloric acid (calculated as H +) is 1.05; and then carrying out two-phase separation on the product feed liquid obtained by neutralization to obtain a water phase containing salt and an organic phase containing diamine and polyamine of diphenylmethane series, refining the organic phase, and carrying out aniline on the organic phase after water washing by adopting a rotary evaporator under the conditions of the temperature of 97 ℃ and the absolute pressure of 80kPaA to obtain refined products of diamine and polyamine of diphenylmethane series.
The isomer of the refined DAM was analyzed by Agilent 1260 Infinity II high performance liquid chromatograph and the pressure difference between the inlet and outlet of the heat exchanger of the reaction unit was detected, and the results are shown in table 1.
Comparative example 2 (compared to example 3)
The preparation of diamines and polyamines (DAM) of the diphenylmethane series is carried out as follows:
S1) adding an aniline stream with the concentration of 94wt% and a hydrochloric acid stream with the concentration of 33wt% into a reactor, and reacting for 10min at the constant temperature of 15 ℃, wherein the molar ratio of catalyst hydrochloric acid (calculated as H +) to aniline (calculated as-NH 2) is 0.40; after the reaction is finished, adding a formaldehyde aqueous solution material flow with the concentration of 37wt%, and maintaining the system temperature at 15 ℃ by adopting a mode of external circulation heat removal and temperature control of a diamine and polyamine reaction solution containing diphenylmethane series in a heat exchanger, wherein the molar ratio of formaldehyde to aniline (calculated by-NH 2) is 0.56;
S2) after the reaction in the first stage is finished, 2S steam (2S steam refers to water vapor with absolute pressure of 0.3 MPaA) is further adopted to heat and adjust the temperature of the system to 95 ℃ outside the system, and the reaction product obtained in the step S1) is subjected to a second-stage reaction at constant temperature for 10min;
S3) after the reaction is finished, heating the system to 100 ℃, and carrying out transposition rearrangement reaction on the reaction product obtained in the step S2) for 2 hours to obtain a reaction product containing diamine and polyamine of diphenylmethane series;
S4) adding a 50wt% sodium hydroxide aqueous solution into the system after the reaction is finished, wherein the reaction temperature is 95 ℃, and stirring and neutralizing the mixture for 30min, wherein the molar ratio of the sodium hydroxide aqueous solution (calculated as OH -) to hydrochloric acid (calculated as H +) is 1.05; and then carrying out two-phase separation on the product feed liquid obtained by neutralization to obtain a water phase containing salt and an organic phase containing diamine and polyamine of diphenylmethane series, refining the organic phase, and carrying out aniline on the organic phase after water washing by adopting a rotary evaporator under the conditions of the temperature of 97 ℃ and the absolute pressure of 80kPaA to obtain refined products of diamine and polyamine of diphenylmethane series.
The isomer of the refined DAM was analyzed by Agilent 1260 Infinity II high performance liquid chromatograph and the pressure difference between the inlet and outlet of the heat exchanger of the reaction unit was detected, and the results are shown in table 1.
Table 1 experimental effects of examples and comparative examples
According to the embodiment of the invention, by adopting a phase change heat transfer temperature control mode of low-bubble point and low-viscosity substances, the problem of equipment blockage in a reaction stage can be avoided, the reaction temperature and the reaction time can be flexibly regulated, the generation proportion of the o-aminobenzyl aniline acid salt and the p-aminobenzyl aniline acid salt can be flexibly regulated, further, 4-MDA isomers with different proportions are generated in a rearrangement process, different market demands of MDI-100 in a downstream product can be met, and the product refinement control is easy to realize. Meanwhile, the invention can skillfully avoid the problem of stable operation of equipment without pursuing to reduce the heavy component content in the product, solves the problem of frequent blockage of heat exchanger equipment caused by adopting a mode of circularly removing heat and controlling temperature of diamine and polyamine reaction liquid containing diphenylmethane series in the prior art, realizes the stable operation of the device in a continuous long period (> 8000 h), and increases annual yield MDI (methylene diphenyl oxide) by more than 16.67% under the same device and working condition.
Compared with the embodiment, in the step S1) and the step S2) of the comparative example 1, the system temperature is maintained by adopting a mode of carrying out external circulation heat removal and temperature control on the diamine and polyamine reaction liquid containing diphenylmethane series in the heat exchanger, and the continuous long period (> 8000 h) stable operation of the device cannot be realized. Although the reaction temperature is controlled by steam heating in step S2) of comparative example 2, the system temperature is maintained by externally circulating the reaction solution containing the diamines and polyamines of diphenylmethane series in the heat exchanger in step S1) to remove heat and control the temperature, and the continuous long-period (> 8000 h) stable operation of the device cannot be realized in the process of increasing the selectivity of the 4,4-MDA isomer.
The foregoing description of embodiments of the invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the spirit of the invention.
Claims (12)
1. The preparation method of 4,4-MDA selectivity controllable di-and polyamine of diphenylmethane series comprises the steps of contacting formaldehyde and aniline in the presence of an acid catalyst, reacting, and then carrying out transposition rearrangement, and is characterized in that the reaction temperatures in different reaction stages are controlled by adopting a phase state change of low-bubble point and low-viscosity substances to carry out heat transfer and temperature control, so that the 4,4-MDA selectivity controllable di-and polyamine of diphenylmethane series is prepared;
the low-bubble point and low-viscosity substance is the existing low-bubble point and low-viscosity substance in the system or an additive with additional low-bubble point and low viscosity;
The low-bubble point and low-viscosity substance has a bubble point ranging from 0 ℃ to 150 ℃ and a viscosity ranging from 0 mPa.s to 10 mPa.s.
2. The preparation method according to claim 1, characterized in that the preparation method comprises the steps of:
S1) carrying out a first-stage reaction of formaldehyde and aniline in the presence of an acid catalyst; in the first-stage reaction, the temperature of the reaction system is controlled by utilizing the phase change of low-bubble point and low-viscosity substances in the system to carry out heat transfer and temperature control;
s2) carrying out second-stage reaction on the reaction product obtained in the step S1); in the second-stage reaction, the temperature control mode of the reaction system is a mode of heat transfer and temperature reduction by utilizing the phase change of low-bubble point and low-viscosity substances in the system or a mode of heating by utilizing steam;
S3) carrying out transposition rearrangement reaction on the reaction product 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, wherein in the first-stage reaction in step S1), the reaction temperature of the first-stage reaction is controlled to be 10-120 ℃ in a temperature control manner;
And, the reaction time of the first stage reaction in the step S1) is 1.5-500 minutes.
4. The method according to claim 2, wherein the temperature control of the first stage reaction in step S1) is performed by vaporizing a low bubble point, low viscosity material already present in the system.
5. The process according to claim 2, wherein in step S1), aniline is pre-reacted by contacting with an acid catalyst before formaldehyde is added to the reaction system, and formaldehyde is then added to continue the reaction;
the reaction temperature after adding formaldehyde is 10-120 ℃.
6. The preparation method according to claim 2, wherein in the second-stage reaction in step S2), the reaction temperature of the second-stage reaction is controlled to be 10-150 ℃ in a temperature control manner;
and the reaction time of the second stage reaction in the step S2) is 1.5-800 minutes.
7. The method according to claim 2, wherein the reaction temperature of the second-stage reaction is the same as or different from the reaction temperature of the first-stage reaction.
8. The method according to claim 2, wherein in step S3), the process conditions of the rearrangement reaction include: the reaction temperature is 55-200 ℃; the reaction time is 1-10 hours.
9. The preparation process according to claim 2, wherein step S1), step S2) and step S3) are carried out in the same reactor or in a plurality of reactors, respectively;
and/or the reaction process of step S1), step S2) and step S3) is carried out in a batch mode or a continuous mode.
10. The preparation method according to claim 2, wherein in step S4), the neutralization reaction is performed by adding an alkali solution, which is one or more of a solution of an alkali metal hydroxide and a solution of an alkaline earth metal hydroxide; the mass concentration of the alkali liquor is 20-55%;
The alkali liquor is calculated by OH -, the acid catalyst is calculated by H +, and the molar ratio of the alkali liquor to the acid catalyst is 1.0-3.0;
And/or the number of the groups of groups,
In step S4), the separation and refinement process includes: and (3) carrying out two-phase separation on the mixed liquid obtained by the neutralization reaction to obtain a water phase containing salt and an organic phase containing diamine and polyamine of diphenylmethane series, and then washing the organic phase with water and removing aniline to obtain the diamine and polyamine products of the diphenylmethane series.
11. The method of any one of claims 1 to 10, wherein the acid catalyst is selected from one or more of an organic acid, an inorganic acid, and a solid acid;
The molar ratio of all the acid catalyst to the aniline used is 0.01-0.80 based on H + of the acid catalyst.
12. The method according to any one of claims 1 to 10, wherein the molar ratio of formaldehyde to aniline is 0.20 to 0.85;
Adding formaldehyde into a reaction system in the form of formaldehyde solution, wherein the mass fraction of formaldehyde in the formaldehyde solution is 15-55%;
the formaldehyde is added into the reaction system in a one-step or multi-step adding mode; the formaldehyde is added into the reaction system by adopting one or more of multi-drop addition, jet addition and direct current addition.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1365454A (en) * | 1971-10-07 | 1974-09-04 | Bayer Ag | Process for the preparation od aromatic polyamines |
| CN114315598A (en) * | 2020-09-29 | 2022-04-12 | 万华化学集团股份有限公司 | Preparation method of diphenylmethane series diamine and polyamine |
| CN117510342A (en) * | 2023-10-26 | 2024-02-06 | 万华化学集团股份有限公司 | Process for the preparation of diamines and polyamines of the diphenylmethane series with improved 2,4-MDA selectivity |
| EP4345088A1 (en) * | 2022-09-29 | 2024-04-03 | Covestro Deutschland AG | A process for preparing di- and polyamines of the diphenyl methane series |
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- 2024-05-11 CN CN202410578990.0A patent/CN118164859A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1365454A (en) * | 1971-10-07 | 1974-09-04 | Bayer Ag | Process for the preparation od aromatic polyamines |
| CN114315598A (en) * | 2020-09-29 | 2022-04-12 | 万华化学集团股份有限公司 | Preparation method of diphenylmethane series diamine and polyamine |
| EP4345088A1 (en) * | 2022-09-29 | 2024-04-03 | Covestro Deutschland AG | A process for preparing di- and polyamines of the diphenyl methane series |
| CN117510342A (en) * | 2023-10-26 | 2024-02-06 | 万华化学集团股份有限公司 | Process for the preparation of diamines and polyamines of the diphenylmethane series with improved 2,4-MDA selectivity |
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