Invention Grant
- Patent Title: Method for production of pyromellitic dianhydride
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Application No.: US10142136Application Date: 2002-05-09
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Publication No.: US06576773B2Publication Date: 2003-06-10
- Inventor: Kenji Nakahara , Tsukasa Takahashi , Shigetaka Takamiya
- Applicant: Kenji Nakahara , Tsukasa Takahashi , Shigetaka Takamiya
- Priority: JP2001-140455 20010510
- Main IPC: C07D49300
- IPC: C07D49300

Abstract:
A method for producing crystals of pyromellitic dianhydride is disclosed which is characterized by setting the water content of an atmosphere used in handling the crystals of pyromellitic dianhydride at a temperature of not higher than 120° C. at a level of not more than 4 vol. %. Particularly by supplying an inert gas having a water content of not more than 4 vol. % to the step of production, it is made possible to prevent the conversion of pyromellitic dianhydride by hydration very efficiently.
Public/Granted literature
- US20020169330A1 Method for production of pyromellitic dianhydride Public/Granted day:2002-11-14
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