Production method of highly pure pyromellitic dianhydride

Details Production method of highly pure pyromellitic dianhydride Production method of highly pure pyromellitic dianhydride

2006-07-21

2009-08-04

Dentz, Bernard (Department: 1625)

Organic compounds -- part of the class 532-570 series

Organic compounds

Heterocyclic carbon compounds containing a hetero ring...

Reexamination Certificate

active

07569707

ABSTRACT:
A method of producing pyromellitic dianhydride. The method includes a step of heating a crude pyromellitic acid in the absence of acetic anhydride to convert a part of pyromellitic acid to pyromellitic anhydride, and a subsequent step of heating the resultant mixture in the presence of acetic anhydride to complete the anhydrization of pyromellitic acid. The pyromellitic dianhydride by the method contains little pyromellitic monoanhydride and other monoanhydrides derived from impurities and is less discolored. The pyromellitic dianhydride has particle properties not causing plugging, etc. during its transportation, storage and use.

REFERENCES:
patent: 1 439 161 (2004-07-01), None
patent: 1 112 817 (1968-05-01), None
patent: 1280562 (1972-07-01), None
patent: 62-59280 (1987-03-01), None
patent: 2000-1484 (2000-01-01), None
patent: 2001-59022 (2001-03-01), None
European Search Report, for Application No. EP 06 11 7497, dated Nov. 23, 2006.

Affiliated with

Also associated with

Rating

Production method of highly pure pyromellitic dianhydride does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Production method of highly pure pyromellitic dianhydride, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Production method of highly pure pyromellitic dianhydride will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-4072917