A method for continuous preparation of 3,3'-dichloro-4,4'-diaminodiphenylmethane

A technology of diaminodiphenyl and methane, which is applied in the field of continuous preparation 3, can solve the problems of continuous post-treatment process, unstable product quality, limited production capacity, etc. Easy to change color during storage and the effect of capacity expansion
CN111675622BActive Publication Date: 2022-03-04JIANGSU RUIXIANG CHEM +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
JIANGSU RUIXIANG CHEM
Publication Date
2022-03-04

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Abstract

The invention relates to a method for continuously preparing 3,3'-dichloro-4,4'-diaminodiphenylmethane. Hydrochloric acid solution, o-chloroaniline and formaldehyde aqueous solution are continuously and simultaneously added dropwise to a primary reactor Salt formation and condensation reaction are carried out in the medium; continuous rearrangement reaction and neutralization reaction are carried out by double-pot switching; continuous oil-water separation and continuous washing are carried out on the product; the purity and chromaticity stability of the obtained MOCA product are significantly improved; The present invention effectively solves the problems of MOCA and unreacted o-chloroaniline, which are ubiquitous in the prior art, are easy to change color after long-term heat storage, and the chromaticity of MOCA products is unstable and the production capacity is limited. Moreover, the synthesis process is automatically and continuously controlled, The overall production efficiency is significantly improved, and the acid consumption, alkali consumption and salty wastewater discharge are significantly reduced, the environmental protection effect is significantly enhanced, and the operation is simple, the economic cost is low, and the production capacity of a single production line is large, which is suitable for popularization and application.
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Description

technical field

[0001] The invention relates to the technical field of fine chemicals, in particular to a method for continuously preparing 3,3'-dichloro-4,4'-diaminodiphenylmethane. Background technique

[0002] 3,3'-dichloro-4,4'-diaminodiphenylmethane is a commonly used aromatic diamine chain extender, commonly known as MOCA, which can be used as a crosslinking agent and curing agent for polyurethane and epoxy resins , can also be used as a vulcanizing agent for rubber, and can also be used to prepare some products with high electrical resistance. It is widely used in automobiles, machinery manufacturing, mining, sports facilities and other fields. DuPont of the United States took the lead in developing the synthesis process of MOCA. This process uses o-chloroaniline, formaldehyde and hydrochloric acid as raw materials. First, o-chloroaniline and hydrochloric acid are reacted to form o-chloroaniline hydrochloride, and then condensed with formaldehyde to form MOCA hydrochl...

Claims

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