Ohlandt, Greeley, Ruggiero & Perle, L.L.P.
Method of preparing polymethylene-polyphenyl-polyamine
The present invention provides a method of preparing polymethylene-polyphenyl-polyamine (briefly referred to as polyamine, DAM), in which a high gravity rotating bed is used as the mixing reactor of formaldehyde and aniline hydrochloride, the mixing solution of aniline hydrochloride and circulation solution and the formaldehyde are fed into the high gravity rotating bed reactor proportionally to carry out mixing and condensation reaction under a condition of a very high gravity; the materials leaving the high gravity rotating bed reactor is introduced into a stirred vessel to proceed with the pre-condensation reaction and obtain a condensation solution; and the process steps of heating, molecular rearrangement, neutralization, water washing and purification, etc. are completed to obtain the refined DAM. With the method according to the present invention, the main by-products is obviously reduced in the condensation process, the phenomenon of deposit attaching to the inner walls of circulation pipes and heat exchanger and blockage are prevented in the condensation process, the impurity content is low in the refined DAM, and the subsequent product MDI has a lighter color, the product quality is stable and may be improved to a certain extent.
Ningbo Wanhua Polyurethanes Co., Ltd. Beijing University of Chemical Technology
C C
C08G C08L
inventional inventional
Weiqi Guangwen Jiansheng Limin Pengyuan Shuchang Haikui Hongke Jianfeng
Hua Chu Ding Xu Zhang Sun Zou Zhang Chen