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Patent Searching and Data


Title:
METHOD FOR PRODUCING AROMATIC TETRACARBOXYLIC DIANHYDRIDE
Document Type and Number:
Japanese Patent JP2002097185
Kind Code:
A
Abstract:

To provide a method for producing highly pure 2,2-bis-(3,4- dicarboxyphenyl)-hexafluororpropane dianhydride having little color.

Highly pure 2,2-bis-(3,4-dicarboxyphenyl)-hexafluororpropane dianhydride having little color is obtained in high yield by oxidizing a 2,2- bis-(3,4-dialkylphenyl)-hexafluoropropane with oxygen or an oxygen-containing gas in the presence of a catalyst constituted of a heavy metal and a halogen in an organic solvent, remove the heavy metal derived from the catalyst as heavy metal ions by adjusting a water content in the crude oxidation reaction liquid without isolating the obtained tetracarboxylic acid, subsequently dehydronizing the tetracarboxylic acid to the dianhydride.


Inventors:
MASAMI HIROSHI
Application Number:
JP2000284788A
Publication Date:
April 02, 2002
Filing Date:
September 20, 2000
Export Citation:
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Assignee:
NEW JAPAN CHEM CO LTD
International Classes:
C07D307/89; B01J31/04; B01J31/26; B01J31/30; C07B61/00; C08G63/682; C08G69/42; C08G73/10; (IPC1-7): C07D307/89; B01J31/04; B01J31/26; B01J31/30