Process for the preparation of diamines and polyamines of the diphenylmethane series
By optimizing the mixing characteristic parameter M of the pre-reaction liquid, the problems of N-methyl impurities and macromolecular polymers caused by uneven mixing of aniline and formaldehyde were solved, achieving high quality of DAM products and long-term stable operation of the equipment.
CN117865817BActive Publication Date: 2026-07-10WANHUA CHEM GRP CO LTD
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- WANHUA CHEM GRP CO LTD
- Filing Date
- 2023-12-26
- Publication Date
- 2026-07-10
Smart Images
Figure QLYQS_1 
Figure BDA0004629836960000031 
Figure BDA0004629836960000151
Abstract
The application belongs to the technical field of diamine and polyamine of diphenylmethane series, and particularly relates to a preparation method of diamine and polyamine (DAM) of diphenylmethane series, that is, before a condensation reaction, a mixing characteristic parameter 1.0<=M<=1.5 of a pre-reaction liquid for the condensation reaction is controlled; the pre-reaction liquid is a mixed liquid formed after a mixture of a formaldehyde solution and aniline hydrochloride or a mixture of the formaldehyde solution and aniline hydrochloride / condensation reaction liquid is pre-mixed. In the method, the mixing characteristic parameter M is controlled in a suitable range, so that the content of N-methyl impurities and the content of macromolecular polymers in the DAM product can be maximally reduced, and the running stability of a production device and the quality of downstream products can be improved.
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