公开(公告)号：US11958806B2

公开(公告)日：2024-04-16

申请号：US17037164

申请日：2020-09-29

Applicant: UNITIKA LTD.

Inventor： Yuki Yamada ,  Tatsuya Morikita ,  Yosuke Sugimoto ,  Takeshi Yoshida ,  Akira Shigeta ,  Yoshiaki Echigo

IPC: C07D207/448 ,  B01D9/00 ,  B01D11/04 ,  C07C267/00

CPC classification number: C07D207/448 ,  B01D9/005 ,  B01D11/0492 ,  C07C267/00

Abstract: An object is to provide a method for easily producing maleimide (MI) in which trace amounts of residual acid components as impurities in a crude MI are efficiently reduced, that is, the acid value is sufficiently reduced.



A method for producing purified MI, comprising reducing an acid value of crude MI by 50% or more, by adding carbodiimide (CDI) to a solution comprising the crude MI to react an acid component in the crude MI with the CDI.
The method for producing purified MI, comprising adding 0.5% by mass or more and 8% by mass or less of the CDI with respect to a mass of the crude MI for reaction.
The method for producing purified MI, wherein the CDI is N,N′-diisopropyl carbodiimide (DIC).
The method for producing purified MI, comprising removing a urea derivative of the CDI (CDI-U) by-produced when reacting the acid component in the crude MI with the CDI.

公开(公告)号：US20210009516A1

公开(公告)日：2021-01-14

申请号：US17037164

申请日：2020-09-29

Applicant: UNITIKA LTD.

Inventor： Yuki Yamada ,  Tatsuya Morikita ,  Yosuke Sugimoto ,  Takeshi Yoshida ,  Akira Shigeta ,  Yoshiaki Echigo

IPC: C07D207/448 ,  B01D11/04 ,  B01D9/00

Abstract: An object is to provide a method for easily producing maleimide (MI) in which trace amounts of residual acid components as impurities in a crude MI are efficiently reduced, that is, the acid value is sufficiently reduced. A method for producing purified MI, comprising reducing an acid value of crude MI by 50% or more, by adding carbodiimide (CDI) to a solution comprising the crude MI to react an acid component in the crude MI with the CDI. The method for producing purified MI, comprising adding 0.5% by mass or more and 8% by mass or less of the CDI with respect to a mass of the crude MI for reaction. The method for producing purified MI, wherein the CDI is N,N′-diisopropyl carbodiimide (DIC). The method for producing purified MI, comprising removing a urea derivative of the CDI (CDI-U) by-produced when reacting the acid component in the crude MI with the CDI.