Title:
METHOD FOR STABILIZING THIOCARBOHYDRAZIDE
Document Type and Number:
Japanese Patent JP3225280
Kind Code:
B2
Abstract:
PURPOSE: To stabilize thiocarbohydrazide, excellent in preservation stability for a long period and useful as a photographic parent chemical, etc., without causing blackening by treating the thiocarbohydrazide with a chelating agent.
CONSTITUTION: Thiocarbohydrazide is stabilized by carrying out the treatment such as recrystallization thereof in the presence of a chelating agent having a higher complex stability constant than that of the thiocarbohydrazide such as ethylenediaminetetraacetic acid or nitrilotriacetic acid, mixing thereof with the chelating agent, washing thereof with a solution containing the chelating agent or addition, etc., of the chelating agent to a production process for the thiocarbohydrazide.
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Inventors:
Tsukasa Maekawa
Hiroyasu Hayashi
Kamiya first
Hiroyasu Hayashi
Kamiya first
Application Number:
JP10388993A
Publication Date:
November 05, 2001
Filing Date:
April 30, 1993
Export Citation:
Assignee:
Otsuka Chemical Co., Ltd.
International Classes:
C07B63/00; C07B63/02; C07C337/06; C09K3/00; (IPC1-7): C07C337/06; C07B63/00; C07B63/02; C09K3/00
Domestic Patent References:
| JP5084530A | ||||
| JP5379821A | ||||
| JP5524545A |
Attorney, Agent or Firm:
Eiji Saegusa (4 others)