Title:
PROCESS FOR PRODUCING DIHYDROXYDIPHENYL SULFONE
Document Type and Number:
WIPO Patent Application WO/2003/091206
Kind Code:
A1
Abstract:
A process for producing dihydroxydiphenyl sulfone in which only trihydroxytriphenyl disulfone and coloring impurities are effectively removed without changing the proportion of dihydroxydiphenyl sulfone isomers. The process for producing dihydroxydiphenyl sulfone is characterized by dissolving or suspending crude dihydroxydiphenyl sulfone containing trihydroxytriphenyl disulfone in an aqueous solvent, regulating the pH of the solution or suspension to 5 to 7, optionally cooling it, and separating out the dihydroxydiphenyl sulfone crystals precipitated.
Inventors:
OI FUMIO (JP)
YANASE NORIO (JP)
KITAHARA TAKAYUKI (JP)
NATE NOBUYUKI (JP)
YANASE NORIO (JP)
KITAHARA TAKAYUKI (JP)
NATE NOBUYUKI (JP)
Application Number:
PCT/JP2003/005228
Publication Date:
November 06, 2003
Filing Date:
April 24, 2003
Export Citation:
Assignee:
KONISHI CHEM IND (JP)
OI FUMIO (JP)
YANASE NORIO (JP)
KITAHARA TAKAYUKI (JP)
NATE NOBUYUKI (JP)
OI FUMIO (JP)
YANASE NORIO (JP)
KITAHARA TAKAYUKI (JP)
NATE NOBUYUKI (JP)
International Classes:
C07C315/06; C07C317/22; (IPC1-7): C07C315/06; C07C317/22
Foreign References:
| JPH10139756A | 1998-05-26 | |||
| JPH1025277A | 1998-01-27 | |||
| EP0220855A1 | 1987-05-06 |
Other References:
See also references of EP 1498412A4
Attorney, Agent or Firm:
Saegusa, Eiji (1-7-1 Doshomachi, Chuo-k, Osaka-shi Osaka, JP)
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