Title:
METHOD OF PURIFYING POLYCYCLIC DYES
Document Type and Number:
WIPO Patent Application WO2002094942
Kind Code:
A9
Abstract:
The disclosed invention pertains to technology of fabricating and purifying synthetic dyes and may be used in various areas of industry and national economy, particularly in fabrication of materials for polarizing coatings of various purposes. In this method of purifying polycyclic dyes, the original dye is processed at least once with concentrated hydrochloric acid in the presence of at least one nitrogen-containing organic compound, such as heterocyclic base and/or aliphatic and/or aromatic amine, and/or quaternary ammonium salt in the amount of 0.1-5% of the weight of the dye at 50-100 DEG C with subsequent filtration. After that, the obtained press-cake is processed at least once with boiling glacial ascetic acid with subsequent hot filtration of the suspension. Obtained sediment is washed with distilled water, after which the sediment is repulped in water, filtered and dried.
Inventors:
NAZAROV VICTOR VASILIEVICH (RU)
SIDORENKO ELENA NIKOLAEVNA (RU)
SIDORENKO ELENA NIKOLAEVNA (RU)
Application Number:
PCT/US2002/016200
Publication Date:
April 10, 2003
Filing Date:
May 21, 2002
Export Citation:
Assignee:
OPTIVA INC (US)
NAZAROV VICTOR VASILIEVICH (RU)
SIDORENKO ELENA NIKOLAEVNA (RU)
NAZAROV VICTOR VASILIEVICH (RU)
SIDORENKO ELENA NIKOLAEVNA (RU)
International Classes:
C07J41/00; C09B67/54; (IPC1-7): C09B47/04; C09B11/10; C09B67/10
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